As filed the Securities and Exchange Commission on August 6, 1997.

Registration No. 333-31049

                      SECURITIES AND EXCHANGE COMMISSION
                           Washington, D.C.  20549

                               AMENDMENT NO. 2
                                     TO
                                  FORM S-3
                            REGISTRATION STATEMENT
                                   UNDER
                          THE SECURITIES ACT OF 1933

                          OLD SECOND BANCORP, INC.
            (Exact name of registrant as specified in its charter)


              Delaware                                    36-3143493
(State or other jurisdiction of incorporation      (I.R.S. employer
  or organization)                               identifiecation no.)

                     37 South River Street
                    Aurora, Illinois  60507
                         (630) 892-0202
(Address, including zip code, and telephone number, including area code, of
           registrant's principal executive offices)
                       Ronald J. Carlson
                     37 South River Street
                    Aurora, Illinois  60507
(Name, address, including zip code, and telephone number, including area code,
                     of agent for service)
                  Copies of Communications to:
                       Eric F. Fess, Esq.
                      Chapman and  Cutler
                        111 West Monroe
                    Chicago, Illinois  60603

     Approximate date of commencement of proposed sale to public:From time 
to time after the Registration Statement becomes effective at the discretion
of the Selling Stockholders.  

     If the only securities being registered on this Form are being
offered pursuant to dividend or interest reinvestment plans, please
check the following box.  [     ]  

     If any of the securities being registered on this Form are to
be offered on a delayed or continuous basis pursuant to Rule_415
under the Securities Act of 1933, other than securities offered
only in connection with dividend or interest reinvestment plans,
please check the following box.  [ x ]

     If this Form is filed to register additional securities for an
offering pursuant to Rule_462(b) under the Securities Act, please
check the following box and list the Securities Act registration
statement number of the earlier effective registration statement
foil the same offering.  [     ]

     If this Form is a post-effective amendment filed pursuant to
Rule_462(c) under the Securities Act, check the following box and
list the Securities Act registration statement number of the
earlier effective registration statement for the same offering.  [ 
   ]
     If delivery of the prospectus is expected to be made pursuant
to Rule_434, please check the following box.  [   ]

The registrant hereby amends this registration statement son such date or 
dates as may be necessary to delay its effective date until the registrant
shall file a further amendment which specifically states that this 
registration statement shall thereafter become effective in accordance with
Section 8(A) of the Securities Act of 1933 or until this registration
statement shall become effective on such date as the Securities and Exchange
Commission, acting pursuant to said Section 8(A), may determine.



          Subject to Completion, Dated August 6, 1997.
                         111,706 Shares
                    Old Second Bancorp, Inc.
                          Common Stock

     This Prospectus relates to 111,706 Shares (the "Shares") of
Common Stock, without par value, (the "Common Stock") of Old Second
Bancorp, Inc., a Delaware corporation ("Old Second") which are being
sold by certain stockholders of the Company (the "Selling
Stockholders").  Old Second will not receive any of the proceeds
from the sale of the Shares offered hereby.  See "Selling
Stockholders."

     The Common Stock is traded on the Nasdaq National Market
System under the symbol OSBC.  On August 1, 1997, the closing price
of the Common Stock on the Nasdaq National Market System was
$47.25.

     These Securities have not been approved or disapproved by the Securities
and Exchange Commission or any state securities commission, nor has the 
Securities and Exchange Commission or any state securities commission passed
upon the accuracy or adequacy of this Prospectus.  Any representation To the
contrary is A criminal offense.

     The Selling Stockholders, or any of them, may sell the Shares
from time to time in transactions on the Nasdaq National Market
System or in the over-the-counter market, or through private sales. 
All sales made on the Nasdaq National Market System or in the over-
the-counter market shall be made at the then prevailing price of
the Shares on such national market system or in such over-the-
counter market, as applicable; any private sales will be made at
negotiated prices.  Sales of the Shares may be made to or through
broker-dealers, and such broker-dealers may receive compensation in
the form of discounts, concessions or commissions from the Selling
Stockholders effecting such sales.  The Selling Stockholders and
any broker-dealers who act in connection with sales of Shares may
be deemed to be "underwriters" as that term is defined in the
Securities Act of 1933, as amended (the "Securities Act"), and any
commissions received by them and profit on any resale of the Shares
may be deemed to be underwriting discounts and commissions under
the Securities Act.  Old Second has agreed to indemnify the Selling
Stockholders and underwriters of the Selling Stockholders against
certain liabilities, including certain liabilities under the
Securities Act, in connection with the registration and the
offering and sale of the Shares offered hereby.  See "Manner of
Offering."

The date of this Prospectus is August  1997.
     


No person has been authorized to give any information or to
make any representation other than those contained in this
Prospectus, and, if given or made, such other information or
representation must not be relied upon as having been authorized. 
This Prospectus does not constitute an offer to sell, or a
solicitation of an offer to buy, the Shares in any jurisdiction
where, or to any person to whom, it is unlawful to make such offer
or solicitation.  Neither the delivery of this Prospectus nor any
sale made hereunder shall, under any circumstances, create an
implication that there has been no change in the affairs of Old
Second since the date hereof or that the information contained
herein or therein is correct as of any time subsequent to the date
of such information.

Available Information

     Old Second is subject to the informational requirements of the
Securities Exchange Act of 1934, as amended (the "Exchange Act"),
and in accordance therewith files reports, proxy statements and
other information with the Securities and Exchange Commission (the
"Commission").  Such reports, proxy and information statements and
other information, including the documents incorporated by
reference herein, can be inspected and copied at the public
reference facilities maintained by the Commission at 450 Fifth
Street, N.W., Washington, D.C. 20549; and at the Commission's
regional offices at Seven World Trade Center, 13th Floor, New York,
New York 10048 and Suite 1400, 500 West Madison Street, Chicago,
Illinois 60661.  Copies of such material can be obtained from the
Public Reference Section of the Commission, 450 Fifth Street, N.W.,
Washington, D.C. 20549 at prescribed rates.  The Commission
maintains a Website at http:\\www.sec.gov that contains reports,
proxy statements and other information filed by Old Second.

     Old Second has filed a registration statement on Form_S-3
(herein, together with all amendments and exhibits, referred to as
the "Registration Statement") under the Securities Act, with respect
to the Common Stock being offered pursuant to this Prospectus. This
Prospectus does not contain all of the information set forth in the
Registration Statement, certain parts of which are omitted in
accordance with the rules and regulations of the Commission.  The
Registration Statement may be inspected and copied at the public
reference facilities maintained by the Commission at the addresses
set forth in the preceding paragraph.  Statements contained herein
concerning the provisions of any documents are not necessarily
complete and, in each instance, reference is made to the copy of
such document filed as an exhibit to the Registration Statement or
otherwise filed with the Commission.  Each such statement is
qualified in its entirety by such reference.

Incorporation of Certain Information by Reference

The following documents, which have been filed by Old Second with
the Commission, are hereby incorporated by reference:

                                Page 2

     1.   Old Second's Annual Report on Form_10-K for the year
     ended December 31, 1996 (which incorporates by reference
     certain information from Old Second's Proxy Statement relating
     to the 1996 Annual Meeting of Stockholders).
    
     2.   Old Second's Quarterly Report on Form_10-Q for the
     quarter ended March_3l, 1997.
     
     3.   Old Second's Current Report on Form_8-K dated May
     20, 1997.
     
     4.   Old Second's Current Report on Form_8-K dated
     August 1, 1997.
         
     5.   The description of Common Stock contained in Old
     Second's registration statement filed pursuant to the Exchange
     Act, and any amendment or report filed for the purpose of
     updating such description.

     All documents filed by Old Second pursuant to Sections_13(a),
13(c), 14 or 15(d) of the Exchange Act after the date of this
Prospectus and prior to the termination of this offering shall be
deemed to be incorporated herein by reference.  Any statement
contained herein or in a document incorporated or deemed to be
incorporated by reference herein shall be deemed to be modified or
superseded for purposes of this Prospectus and the Registration
Statement of which it is a part to the extent that a statement
contained herein or in a subsequently filed document which also is
incorporated or deemed to be incorporated by reference herein
modifies or supersedes such statement.  Any statement so modified
or superseded shall not be deemed, except as so modified or
superseded, to constitute a part of this Prospectus or such
Registration Statement.

     Old Second will provide without charge to each person to whom
a copy of this Prospectus has been delivered, upon written or oral
request of such person, a copy of any or all of the documents which
have been or may be incorporated herein by reference, other than
exhibits to such documents (unless such exhibits are specifically
incorporated by reference into such documents).  Requests for such
copies should be directed to Ronald_J. Carlson, President, Old
Second Bancorp, Inc., 37_South River Street, Aurora, Illinois 
60507, telephone number (630)_892-0202.
Old Second Bancorp, Inc.

     Old Second, a Delaware corporation, is a multibank holding
company registered under the BHCA and based in Aurora, Illinois. 
Old Second owns 100% of the capital stock of The Old Second
National Bank of Aurora, Yorkville National Bank, The Old Second
Community Bank of North Aurora, The Old Second Community Bank of
Aurora, Burlington Bank, Kane County Bank and Trust Company and
Bank of Sugar Grove (the "Old Second Subsidiary Banks").  In May
1997, Old Second completed the acquisition of Maple Park
Bancshares, Inc. which owned 100% of the capital stock of the First
State Bank of Maple Park.  In June 1997, First State Bank of Maple
Park merged with The Old Second National Bank of Aurora.
                             Page 3

     The Old Second National Bank of Aurora (the "Old Second
National Bank"), located at 37_South River Street, Aurora,
Illinois, offers complete banking and trust services for retail,
commercial, industrial, and public entity customers in Aurora,
Illinois and the surrounding area.  Services include loans to all
customer segments, checking, savings and time deposits; lock box
service and safe deposit boxes; trust and other fiduciary services
to commercial customers and individuals; and other customer
services.  Old Second National Bank has two offsite automatic
teller machines, and its customers can use certain other financial
institutions' offsite teller machines to complete deposit,
withdrawal, transfers, and other banking transactions.

     The Old Second Community Bank of North Aurora is located at
200_West John Street in the Village of North Aurora.  The Old
Second Community Bank of Aurora is located at 1350 North Farnsworth
Avenue, Aurora, Illinois.  Yorkville National Bank is located at
102_East Van Emmon Street, Yorkville, Illinois.  Burlington Bank is
located at 194_South Main Street, Burlington, Illinois.  Kane
County Bank and Trust Company is located at 122_North Main Street,
Elburn, Illinois.  Bank of Sugar Grove is located on Cross Street
at Route_47, Sugar Grove, Illinois.

     These banks offer banking services for retail, commercial,
industrial, and public entity customers in the Aurora, North
Aurora, Yorkville, Burlington, Elburn, Wasco, Plano, Oswego, Ottawa
and Maple Park communities and surrounding areas.  Services include
loans to all customer segments, checking, savings and time
deposits, and other customer services.  With the exception of
Yorkville's main banking facility, these banks have onsite 24-hour
automatic teller machines, and their customers can use certain
other financial institutions' offsite teller machines to complete
deposit, withdrawal, transfers, and other banking transactions. 
Customers can enjoy "Valley-Wide Banking" at all Old Second
Subsidiary Bank locations.  A customer of an Old Second Subsidiary
Bank can transact most business, including checking, savings and
personal loan transactions, at any other Old Second Subsidiary
Bank.

Recent Developments

     In connection with the acquisition of Maple Park Bancshares,
Inc. by Old Second in May 1997, Old Second agreed, pursuant to a
Registration Rights Agreement dated May_13, 1997 (the "Registration
Rights Agreement"), to register all shares of Common Stock issued
to the former Maple Park Bancshares, Inc. stockholders in exchange
for their shares of Maple Park Bancshares, Inc.  These stockholders
are identified herein under "Selling Stockholders."

Proceeds of the Offering

     Old Second will not receive any proceeds from the sale of
Common Stock offered hereby.
                             Page 4

Price Range of Common Stock and Dividend Policy

     Old Second Common Stock currently trades on the Nasdaq
National Market System under the symbol "OSBC."  The following table
sets forth the range of closing prices and dividend information
during the periods indicated for 1997, 1996 and 1995.


     
     1997                    High      Low     Dividends 
                                               Declared
                                         
 First Quarter             $48.50    $46.75      $.20

 Second Quarter             48.50     47.50      $.20

 Third Quarter
  (through August_1,
   1997)                    48.75     46.75       ---


    1996                     High      Low     Dividends
                                               Declared

 First Quarter             $37.60    $36.00      $.16

 Second Quarter             39.00     38.50       .20

 Third Quarter              40.00     38.75       .20

 Fourth Quarter             41.50     39.25       .30


     1995                    High      Low     Dividends
                                               Declared

 First Quarter             $34.00    $27.20      $.14

 Second Quarter             36.00     28.80       .14

 Third Quarter              37.00     29.60       .16

 Fourth Quarter             41.00     32.80       .28


     The last reported closing price of Old Second Common Stock on
August 1, 1997, was $47.25.

     Old Second presently expects that it will continue to pay
dividends on the Common Stock in the future at such times and in
such amounts as Old Second's Board of Directors, in its discretion,
may determine.  For additional information regarding payment of
dividends, see "Description of Capital Stock Dividend Rights."
Selling Stockholders

     All of the shares of Common Stock being offered hereby are
being sold by the Selling Stockholders.  Each of the Selling
Stockholders acquired their shares of Common Stock in connection
with the acquisition by Old Second of Maple Park Bancshares, Inc.,
consummated in May 1997.  After completion of the offering
contemplated hereby, none of the Selling Stockholders will
beneficially own more than 1% of the Common Stock.

                            Page 5

     The following table sets forth the name of each Selling
Stockholder and certain information regarding the beneficial
ownership of Common Stock as of August 1, 1997 and as adjusted to
reflect the sale of the Shares by the Selling Stockholders.

                              Shares            Shares          Shares
Name of                   Owned Prior to        Offered       Owned after
Selling Stockholder        the Offering         Hereby        the Offering
                                                         
Joe A. Pruess                 42,252            42,252             0
Bruce Madden (1)              30,222            30,222             0
Maple Park Bancshares, Inc.
 Employee Stock Ownership
 Trust                        25,790            25,790             0
John F. and Kostia Pappas      2,525             2,525             0
Justin R. Krupp                1,034             1,034             0
Bridget A. Krupp               1,034             1,034             0
Thomas J. Krupp, II            1,034             1,034             0
James C. Krupp                 1,034             1,034             0
Vincent and Anna Palazzolo     1,263             1,263             0
William E. Phillips              631               631             0
Leo E. and Patricia Elliott      252               252             0
Edward A. Rosenow                400               400             0
Richard and Kenneth Hintzsche  1,262             1,262             0
Robert R. Bowman               1,039             1,039             0
Mark Ringhouse                   391               391             0
Charles J. and Lynn A.
   Shepard                       450               450             0
Erin S. Pruess                   384               384             0
Jill E. Pruess                   384               384             0
Bertha and Mark A. Williams      136               136             0
Cari L. and Kenneth R. Zwick     136               136             0
Jeffrey S. and Todd E. Madden     53                53             0

     Total:                  111,706           111,706             0

<FN>
____________________
(1)  Mr. Madden currently serves as Chief Executive Officer of
     Maple Park Mortgage Company, a wholly owned subsidiary of Old
     Second.


                                   Page 6

Description of Capital Stock

     The authorized capital stock of Old Second consists of 300,000
shares of Preferred Stock, without par value, and 6,000,000 shares
of Common Stock, without par value.  As of August_1, 1997, there
was no Preferred Stock outstanding and 3,049,190 shares of Common
Stock were outstanding.

Dividend Rights

     Holders of Common Stock are entitled to receive such dividends
as are declared by its Board of Directors out of funds legally
available therefore.  Because Old Second's consolidated net income
consists largely of the net income of the Old Second Subsidiary
Banks, Old Second's ability to pay dividends depends, in part, upon
its receipt of dividends from such banks.

Voting Rights   Non-Cumulative Voting

     Holders of shares of Common Stock are entitled to one vote for
each share of stock held by them.

     The shares of Common Stock do not have cumulative voting
rights.  This means that the holders of more than 50% of the shares
of Common Stock voting for the election of directors can elect 100%
of the class of directors standing for election at any meeting if
they choose to do so, and in such event, the holders of the
remaining shares voting for the election of directors will not be
able to elect any person or persons to Old Second's Board of
Directors at such meeting.

Preemptive Rights

     The holders of Common Stock have no preemptive rights.
Other Matters

     The Common Stock has no conversion rights, and is not subject
to any redemption or sinking fund provisions or any further calls
or assessments.  The shares of Common Stock currently outstanding
are fully paid and nonassessable.

     Subject to the preferential rights, if any, of any preferred
stock that may be issued in the future, holders of shares of Common
Stock are entitled to receive such dividends as may be declared
from time to time by Old Second's Board of Directors from the
assets of Old Second legally available therefor and, upon any
liquidation of Old Second, a pro rata share of all assets of Old
Second available for distribution to shareholders.

                             Page 7

Certain Provisions of Old Second's Restated Certificate of Incorporation

     Old Second's Restated Certificate of Incorporation (the
"Restated Certificate") and Bylaws differ from the charter of Maple
Park in certain material respects.  These differences, which are
described below, are intended to encourage any person interested in
acquiring Old Second to obtain the approval of its Board of
Directors and to discourage takeovers by persons intending to
eliminate the remaining stockholders' interest in a reorganization. 
Old Second believes that, in such a situation, the ability of the
Board of Directors to represent effectively the interests of its
stockholders will thereby be enhanced.  However, a change in
control of Old Second which is opposed by the Board of Directors
could be made more difficult by these provisions, even if such a
change were desired by a majority of the stockholders of Old
Second.  Old Second is not aware of any person who intends to
acquire Old Second or seek a change in control of Old Second.

     Preferred Stock.  Old Second is authorized to issue up to
300,000 shares of Preferred Stock, without par value (the
"Preferred Stock").  No shares of the Preferred Stock are
outstanding.  The Preferred Stock is issuable in series established
from time to time by the Board without further action by the Old
Second stockholders.  The Board of Directors of Old Second has
broad authority to fix the number of shares included in each series
and the designation, relative powers, preferences and rights, and
the qualifications, limitations or restrictions of each series,
including but not limited to dividend rates, redemption rights,
conversion rights, voting rights (not to exceed one vote per share)
and liquidation preferences.

     The authorized but unissued shares of Preferred Stock could be
used by incumbent management to make a change in control of Old
Second more difficult.  Under certain circumstances such shares
could be used to create voting impediments or to frustrate persons
seeking to effect a takeover or otherwise gain control of Old
Second.  Such shares could be privately placed with purchasers who
might side with the Board of Directors in opposing a hostile
takeover bid.

     Elimination of Stockholder Action by Consent.  Pursuant to
Delaware law, unless otherwise provided in the certificate of
incorporation, any action required or permitted to be taken by
stockholders may be taken without a meeting and without a
stockholder vote if a written consent setting forth the action to
be taken is obtained.  The Restated Certificate provides that
stockholder action may only be taken at an annual or special
meeting of stockholders and prohibits stockholder action by
consent.

     This provision prevents the holders of a majority of the
voting power of Old Second (or any other stockholders, for that
matter) from using the written consent procedure to take
stockholder action (although federal proxy rules might apply to the
solicitation of such consents).

                              Page 8

     Classification of the Board of Directors.  Article_X of the
Restated Certificate provides the following:

     (1)   Paragraph_A provides that the Board shall consist of
     a minimum of five and a maximum of twenty-five directors.  The
     Board currently consists of fourteen members.  Paragraph_A
     also authorizes the Board or the stockholders to determine the
     number of directors to be elected in the future.

     (2)   Paragraph_B (as discussed below) provides for a
     classified Board.

     (3)   Paragraph_C (as discussed below) provides that
     vacancies on the Board may be filled by a majority of the
     directors then in office, though less than a quorum, or by a
     sole remaining director, and that a director chosen to fill a
     vacancy shall hold office until the expiration of the term of
     the class for which such director is chosen.

     (4)   Paragraph_D authorizes vacancies and newly created
     directorships of any series of Preferred Stock to be filled by
     a majority of the directors elected by the holders of such
     series then in office or by a sole remaining director so
     elected.

     (5)   Paragraph_E provides that, unless provided for in
     the Bylaws, the election of directors need not be by written
     ballot.

     (6)   Paragraph_F (as discussed below) provides for
     advance notification of nominations for directors.

     (7)   Paragraph_G (as discussed below) provides that
     directors of Old Second may be removed from the Board only for
     cause and by the affirmative vote of the holders of 66-2/3% of
     the then outstanding capital stock eligible to vote thereon.

     (8)   Paragraph_H provides that the business of Old Second
     shall be managed by the Board and authorizes the Board to
     exercise all powers not reserved for the stockholders.

     (9)   Paragraph_I authorizes a limit on certain
     liabilities of directors of Old Second.  See "Limitation of
     Director Liability."

     Classified Board.  Article_X of the Restated Certificate
provides that the Board be divided into three classes as nearly
equal in number as possible.

     The provisions of this Article provide that any vacancy in the
membership on the Board, resulting from an increase in the
authorized number of directors, retirement, resignation, removal,
or death, will be filled by the Board acting by a majority of the
directors then in office, and any director so chosen shall serve
for the remainder of the then present term of office of the class
in which the vacancy shall have occurred or shall have been
created.

                           Page 9

     The provisions of this Article make it more difficult and
time-consuming to change majority control of the Board and thus
reduce the vulnerability of Old Second to an unsolicited proposal
for the takeover of Old Second that does not contemplate the
acquisition of all of the Old Second outstanding shares, or an
unsolicited proposal for the restructuring or sale of all or part
of Old Second.

     The provisions of this Article may have significant effects on
stockholders' ability to change the composition of the incumbent
Board and to benefit from certain transactions which are opposed by
the incumbent Board.

     The provisions of this Article may discourage or make more
difficult a proxy contest or the assumption of control by a holder
of a substantial block of the Old Second stock or the removal of
the incumbent Board and could increase the likelihood that
incumbent directors will retain their positions.

     Advance Notice Nomination of Directors.  Paragraph_F of
Article_X of the Restated Certificate requires any stockholder
desiring to nominate a person to the Board to give not less than
fourteen days nor more than sixty days prior notice of such
nomination.  Such notice shall contain certain required information
concerning the nominee, including his name, address, principal
occupation and number of shares of stock of Old Second beneficially
owned by such nominee and by the nominating stockholder. 
Nominations not made in accordance with the procedure set forth in
Article_X shall be disregarded.

     A possible effect of this provision may be that persons
otherwise qualified to serve as directors and who are proposed for
nomination and election by holders of a majority of the outstanding
and voting shares may not be nominated or elected due to the
failure to comply with this procedural requirement, whether due to
inadvertence or otherwise.  Such provision limits the ability of
stockholders to nominate persons for the Board who might be
interested in a change in control of Old Second.

     Increase in Stockholder Vote Required to Remove Directors. 
Pursuant to the Restated Certificate, the vote of the holders of
66-2/3% of the shares of outstanding capital stock of Old Second
eligible to vote thereon are required to remove a director for
cause.  These provisions may have significant effects on
stockholders' ability to change the composition of the incumbent
Board and to benefit from certain transactions which are opposed by
the incumbent Board.

     Circumvention Provision.  Article_XI of the Restated
Certificate provides that the anti-takeover provisions may not be
amended or repealed without the affirmative vote of the holders of
75% of the then outstanding shares of Voting Stock (as defined in
Article_XII).  This provision is designed to prevent circumvention
of the anti-takeover provisions of the Restated Certificate but
would make it more difficult for the stockholders of Old Second to
amend the Restated Certificate if the incumbent Board opposes such
amendment.

                              Page 10

     Fair Price Provision.  Article_XII of the Restated Certificate
requires that certain procedural safeguards for the protection of
noncontrolling stockholders be observed by a Related Person (as
defined in Article_XII) if such Related Person seeks to effect a
merger or certain other business combination ("Business
Combination") which could eliminate or fundamentally change the
interest of the noncontrolling stockholders.  If these procedures
are not complied with, or if the proposed Business Combination is
not approved by a majority of the directors of Old Second who are
unaffiliated with, and not a nominee of, the Related Person and
either were members of the Board prior to the time that the Related
Person became a Related Person or were recommended to succeed a
Continuing Director by a majority of Continuing Directors on the
Board at the time of such recommendation (the "Continuing
Directors"), Article_XII requires that the Business Combination
with the Related Person be approved by the holders of at least 75%
of the outstanding Voting Stock (the "75% Stockholder Vote
Requirement").  In the event that the requisite approval of the
Board was given with respect to a particular Business Combination
or the price criteria and procedural safeguards were satisfied,
only a majority vote of the outstanding Voting Stock would be
required.

     Tender offers or other non-open market acquisitions of stock
are usually made at prices above the prevailing market price of a
corporation's stock.  In addition, acquisitions of stock by persons
attempting to acquire control through market purchase may cause the
market price of stock to reach levels which are higher than would
otherwise be the case.

     Article_XII may discourage such purchases, particularly those
of less than all Old Second shares, and may thereby deprive holders
of the Old Second's stock of an opportunity to sell their stock at
a premium above the market price.  Because of the potentially
higher vote requirements for stockholder approval of any subsequent
Business Combination and the possibility of having to pay a higher
price to other stockholders in such a Business Combination, it may
become more costly for a purchaser to acquire control of Old
Second.

     Article_XII may therefore decrease the likelihood that a
tender offer will be made and, as a result, may adversely affect
those stockholders who would desire to participate in a tender
offer.  In addition, a Related Person may be unable, as a practical
matter, to comply with all of the procedural requirements of
Article_XII.  Further, the minimum price required under Article_XII
may not necessarily be indicative of market value.

     Article_XII would also give veto power to the holders of a
minority of the Voting Stock with respect to a Business Combination
which is not approved by a majority of the Continuing Directors but
which a majority of stockholders may believe to be desirable and
beneficial.  As of December_31, 1996, the directors, executive
officers and certain key personnel of Old Second, as a group,
beneficially owned approximately 4.7% of the outstanding shares of
Common Stock.  Article_XII might have the effect of maintaining the
position of incumbent management and might also have the effect
that the Board would have the power to defeat a Business
Combination which is desired by holders of a majority, but less
than 75%, of the Voting Stock.

     Nonmonetary Factors Provisions.  Article_XIII of the Restated
Certificate provides that, in evaluating acquisition proposals, the
Board must take into account not only the consideration to be paid
but also certain nonmonetary factors set forth in Article_XIII. 

                               Page 11

Those factors include:  (a)_the adequacy of the amount to be paid
in connection with any such transaction; (b)_the social and
economic effects of the transaction on Old Second and its
Subsidiaries (as defined in Article_XII), the employees,
depositors, loan and other customers and creditors of Old Second
and its Subsidiaries and the other elements of the communities in
which Old Second and its Subsidiaries operate or are located;
(c)_the business and financial condition and earnings prospects of
the acquiring person or persons, including, but not limited to,
debt service and other existing or likely financial obligations of
the acquiring person or persons, and the possible effect of such
conditions upon Old Second and its Subsidiaries and the other
elements of the communities in which Old Second and its
Subsidiaries operate or are located; (d)_the competence,
experience, and integrity of the acquiring person or persons and
its or their management; and (e)_any antitrust or other legal or
regulatory issues which may be raised by any such transaction.

     Greenmail Prevention Provision.  Article_XIV of the Restated
Certificate is intended to discourage the speculator who, alone or
with others, accumulates beneficial ownership of a significant
block of stock and then, under the threat of making a tender offer,
launching a proxy contest or instigating some other corporate
disruption or upset, succeeds in extracting from the corporation
involved a premium price for its shares, a tactic which has been
dubbed "greenmail."

     The provisions would, in general, preclude Old Second from
purchasing any Voting Stock at a per share price in excess of the
Fair Market Value (as defined in Article_XII) as of the time of
such purchase from a person known by Old Second to be a Substantial
Stockholder (as defined in Article_XIV) unless such purchase has
been approved by the affirmative vote of the holders of at least
two-thirds of the Voting Stock held by Disinterested Stockholders
(as defined in Article_XIV).  The foregoing limitation would not
apply to (1)_any purchase pursuant to an offer to purchase which is
made on the same terms and conditions to the holders of all of the
outstanding Voting Stock or (2)_any open market purchase that
constitutes a Public Transaction (as defined in Article_XIV).

     Because this provision is designed to discourage accumulations
of large blocks of Old Second's stock by purchasers whose objective
is to have such stock repurchased by Old Second at a premium, this
provision could tend to reduce the temporary fluctuations in the
market price of Old Second's stock which are caused by
accumulations of large blocks of Old Second's stock.  Accordingly,
stockholders could be deprived of possible opportunities to sell
their stock at a temporarily higher market price.

     Limitations of Director Liability.  Paragraph_I of Article_X
of the Restated Certificate eliminates directors' liability to Old
Second or its stockholders for monetary damages arising out of the
directors' breach of their fiduciary duty of care.  This provision
does not affect the directors' liability for monetary damages for
breaches of the duty of loyalty, actions or omissions involving bad
faith, knowing violations of the law or intentional misconduct,
paying an illegal dividend, approving an illegal stock repurchase,
or obtaining an improper personal benefit.

                            Page 12

Manner of Offering

     The Selling Stockholders, or any of them, may sell the Shares
from time to time in transactions on the Nasdaq National Market
System or in the over-the-counter market, or through private sales. 
All sales made on the Nasdaq National Market System or in the over-
the-counter market shall be made at the then prevailing price of
the Shares on such national market system or in such over-the-
counter market, as applicable; any private sales will be made at
negotiated prices.  Sales of the Shares may be made to or through
broker-dealers, and such broker-dealers may receive compensation in
the form of discounts, concessions or commissions from the Selling
Stockholders effecting such sales.  The Selling Stockholders and
any broker-dealers who act in connection with sales of Shares may
be deemed to be "underwriters" as that term is defined in the
Securities Act, and any commissions received by them and profit on
any resale of the Shares may be deemed to be underwriting discounts
and commissions under the Securities Act.

     The Selling Stockholders have advised Old Second that, during
such time as they may be engaged in a distribution of the Shares,
they will comply with Regulation_M, and the rules promulgated
thereunder, under the Exchange Act and, in connection therewith,
the Selling Stockholders have agreed not to engage in any
stabilization activity in connection with Old Second's securities,
to furnish to each broker-dealer through which the Shares may be
offered copies of this Prospectus, and not to bid for or purchase
any securities of Old Second or attempt to induce any person to
purchase any of Old Second's securities except as permitted under
the Exchange Act.  The Selling Stockholders have also agreed to
inform Old Second when the distribution of the Shares is completed.

     Regulation_M, and the rules promulgated thereunder, prohibit
participants in a distribution from bidding for or purchasing, for
an account in which the participant has a beneficial interest, any
of the securities that are subject of the distribution. 
Regulation_M also governs bids and purchases made in order to
stabilize the price of a security in connection with a distribution
of the security.

     The Registration Rights Agreement provides that any public
offering of the Shares by the Selling Stockholders will terminate
on the earlier of (a) May 13, 1998 or (b) the date on which all
Shares have been sold by the Selling Stockholders.  Old Second has
agreed with the Selling Stockholders to prepare and file with the
Commission any amendments or supplements to the Registration
Statement and this Prospectus as may be necessary to keep the
Registration Statement effective through such offering period.

     The Registration Rights Agreement provides that Old Second
indemnify the Selling Stockholders against certain liabilities,
including liabilities under the Securities Act.  The Registration
Rights Agreement also provides for the indemnification of Old
Second by the Selling Stockholders for certain liabilities,
including liabilities under the Securities Act.  In addition, under
the Registration Rights Agreement, Old Second's obligation to
indemnify extends to those who participate in the distribution of
the Common Stock offered hereby as underwriters for the Selling
Stockholders.  Also pursuant to the Registration Rights Agreement,
the Selling Stockholder will pay all applicable stock transfer
taxes, brokerage commissions, underwriting discounts or commissions

                             Page 13

and any fees of Selling Stockholder's counsel and accountants but
Old Second has agreed to pay substantially all fees and expenses
incident to the preparation, filing, amending and supplementing of
the Registration Statement of which this Prospectus is a part.

Validity of the Common Stock

     The validity of the Shares will be passed upon for Old Second
by Schanlaber & Reed, A Professional Corporation, Aurora, Illinois.

Experts

     The consolidated balance sheets of Old Second Bancorp, Inc.
and subsidiaries as of December_31, 1996 and 1995, and the related
consolidated statements of income, changes in stockholders' equity
and cash flows for the two years in the period ended December_31,
1996, incorporated by reference in Old Second Bancorp, Inc.'s
Annual Report (Form_10-K) for the year ended December_31, 1996 have
been audited by Ernst & Young LLP, independent auditors, as set
forth in their report thereon incorporated by reference therein and
incorporated herein by reference.  Such consolidated financial
statements are incorporated herein by reference in reliance upon
such report given upon the authority of such firms as experts in
accounting and auditing.  The consolidated balance sheet of Old
Second Bancorp, Inc. as of December_31, 1994 and the related
consolidated statements of income, changes in stockholders' equity
and cash flows for the year ended December_31, 1994, prior to the
restatement for the 1995 pooling-of-interest, incorporated by
reference in this Registration Statement, have been audited by
Coopers_& Lybrand, L.L.P., independent auditors, as stated in their
report, which is incorporated by reference into this Registration
Statement.

                                 Page 14

No person has been authorized
to give any information or to
make any representations other
than those contained in this
Prospectus, and, if given or
made, such information or
representations must not be
relied upon as having been
authorized.  This Prospectus
does not constitute an offer to
sell or the solicitation of an
offer to buy any securities
other than the securities
described in this Prospectus or
an offer to sell or the
solicitation of an offer to buy
such securities in any
circumstances in which such
offer or solicitation is
unlawful.  Neither the delivery
of this Prospectus nor any sale
made hereunder or thereunder
shall, under any circumstances,
create any implication that
there has been no change in the
affairs of Old Second since the
date hereof or that the
information contained herein or
therein is correct as of any
time subsequent to the date of
such information.
                      ___________________
                       Table of Contents
                      Prospectus Statement
                           Prospectus
                              Page
                                                               
 Available Information            2
 Incorporation of Certain
     Information by Reference     2
 Old Second Bancorp, Inc.         3
 Recent Developments              4
 Proceeds of the Offering         4
 Price Range of Common Stock
     and Dividend Policy          5
 Selling Stockholders             5
 Description of Capital Stock     7
 Manner of Offering              13
Validity of the Common Stock     14
Experts                          14



                         111,706 Shares
                           Old Second
                         Bancorp, Inc.
                         Common Stock,
                       without par value
                        August  , 1997



                            Part II
           Information Not Required in the Prospectus
Item 14.  Other Expenses of Issuance and Distribution.
     Old Second estimates that expenses in connection with the
offering described in this Registration Statement, and which will
be borne by Old Second, will be as follows:


                                                  
Registration fee . . . . . . . . . . . . . . . . . $ 1,654
Printing and engraving expenses. . . . . . . . . . .     0
Legal fees and expenses. . . . . . . . . . . . . . .10,000
Accountants' fees and expenses . . . . . . . . . . .     0
Miscellaneous. . . . . . . . . . . . . . . . . . . .     0

    Total . . . . . . . . . . . . . . . . . . . . .$11,654


Item 15.  Indemnification of Directors and Officers.

     Reference is made to Section_102(b)(7) of the Delaware General
Corporation Law (the "DGCL"), which enables a corporation in its
original certificate of incorporation or an amendment thereto to
eliminate or limit the personal liability of a director to the
corporation or its stockholders for monetary damages for breach of
the director's fiduciary duty, except (i) for any breach of the
director's duty of loyalty to the corporation or its stockholders,
(ii) for acts or omissions not in good faith or which involve
intentional misconduct or a knowing violation of law, (iii)
pursuant to Section_174 of the DGCL (providing for liability of
directors for unlawful payment of dividends or unlawful stock
purchases or redemptions), or (iv) for any transaction from which
the director derived an improper personal benefit.

     Old Second's Restated Certificate includes a provision
eliminating the liability of directors consistent with
Section_102(b)(7) of the DGCL.

     Reference also is made to Section_145 of the DGCL which
provides that a corporation may indemnify any person, including
officers and directors, who is, or is threatened to be made, a
party to any threatened, pending or completed legal action, suit or
proceeding, whether civil, criminal, administrative or
investigative (other than an action by or in the right of such
corporation), by reason of the fact that such person is or was an
officer, director, employee or agent of such corporation, or is or
was serving at the request of such corporation as a director,
officer, employee or agent of another corporation or enterprise. 
The indemnity may include expenses (including attorney's fees),
judgments, fines and amounts paid in settlement actually and
reasonably incurred by such person in connection with such action,
suit or proceeding, if such person acted in good faith and in a
manner he reasonably believed to be in or not opposed to the
corporation's best interests and, with respect to any criminal
proceeding, had no reasonable cause to believe that his conduct was
unlawful.  A Delaware corporation may indemnify its officers,
directors, employees and agents in an action by or in the right of
the corporation under the same conditions, except that no
indemnification is permitted without judicial approval if the
officer, director, employee or agent is adjudged to be liable to
the corporation.  Where an officer, director, employee or agent is
successful on the merits or otherwise in the defense of any action
referred to above, the corporation must indemnify him against the
expenses which such officer, director, employee or agent actually
and reasonable incurred in connection therewith.

     Old Second's Restated Certificate provides for indemnification
of directors and officers of Old Second to the full extent
permitted by the DGCL.  Old Second maintains a directors' liability
policy to insure its liability under the above-described provision
of its Restated Certificate and to insure individual directors
against certain obligations not covered by such provisions.

Item 16.  Exhibits.

*(5)        Opinion of Schanlaber_& Reed, A Professional
            Corporation, regarding the Validity of the Common
            Stock.
*(23) (a)      Consent of Ernst_& Young LLP.
*(23) (b)      Consent of Coopers & Lybrand, LLP.
*(23) (c)      Consent of Schanlaber_& Reed, A Professional
            Corporation (included in Exhibit 5).
____________________
*    Previously filed.

Item 17.  Undertakings.

     The undersigned registrant hereby undertakes:

     (1)   To file, during any period in which offers or sales
     are being made of the securities registered hereby, a post-
     effective amendment to this registration statement:

          (i)   To include any prospectus required by
          Section_10(a)(3) of the Securities Act of 1933;
 
          (ii)   To reflect in the prospectus any facts or
          events arising after the effective date of the
          registration statement (or the most recent post-effective
          amendment thereof) which, individually or in the
          aggregate, represent a fundamental change in the
          information set forth in the registration statement. 
          Notwithstanding the foregoing, any increase or decrease
          in volume of securities offered (if the total dollar
          value of securities offered would not exceed that which
          was registered) and any deviation from the low or high
          and of the estimated maximum offering range may be
          reflected in the form of prospectus filed with the
          Commission pursuant to Rule_424(b) if, in the aggregate,
          the changes in volume and price represent no more than a
          20 percent change in the maximum aggregate offering price
          set forth in the "Calculation of Registration Fee" table
          in the effective registration statement; and

                             Page  II-2

          (iii)   To conclude any material information with
          respect to the plan of distribution not previously
          disclosed in the registration statement or any material
          change to such information in the registration statement;
          provided, however, that paragraphs_(1)(i) and (1)(ii) do
          not apply if the information required to be included in
          a post-effective amendment by those paragraphs is
          contained in periodic reports filed with or furnished to
          the Commission by the registrant pursuant to Section_13
          or Section_15(d) of the Securities Exchange Act of 1934
          that are incorporated by reference in this registration
          statement.

     (2)   That, for the purpose of determining any liability
     under the Securities Act of 1933, each such post-effective
     amendment shall be deemed to be a new registration statement
     relating to the securities offered therein, and the offering
     of such securities at that time shall be deemed to be the
     initial bona fide offering thereof.
 
     (3)   To remove from registration by means of a post-
     effective amendment any of the securities being registered
     which remain unsold at the termination of the offering.

     The undersigned registrant hereby undertakes that, for
purposes of determining any liability under the Securities Act of
1933, each filing of the registrant's annual report pursuant to
Section_13(a) or Section_15(d) of the Securities Exchange Act of
1934 (and, where applicable, each filing of an employee benefit
plan's annual report pursuant to Section_15(d) of the Securities
Exchange Act of 1934) that is incorporated by reference in the
registration statement shall be deemed to be a new registration
statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the
initial bona fide offering thereof.

     Insofar as indemnification for liabilities arising under the
Securities Act of 1933 may be permitted to directors, officers and
controlling persons of the registrant pursuant to the provisions
described under Item 15 above, or otherwise, the registrant has
been advised that in the opinion of the Securities and Exchange
Commission such indemnification is against public policy as
expressed in the Act and is, therefore, unenforceable.  In the
event that a claim for indemnification against such liabilities
(other than the payment by the registrant of expenses incurred or
paid by a director, officer or controlling person of the registrant
in the successful defense of any action, suit or proceeding) is
asserted by such director, officer or controlling person in
connection with the securities being registered, the registrant
will, unless in the opinion of its counsel the matter has been
settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is
against public policy as expressed in the Act and will be governed
by the final adjudication of such issue.

                           Page II-3


                           Signatures

     Pursuant to the requirements of the Securities Act of 1933,
the registrant certifies that it has reasonable grounds to believe
that it meets all of the requirements for filing on Form_S-3 and
has duly caused this amendment to registration statement to be
signed on its behalf by the undersigned, thereunto duly authorized,
in the City of Aurora, State of Illinois, on August_4, 1997.

                                   Old Second Bancorp, Inc.

                                   By /s/ James E. Benson

                                   Chairman, Chief Executive
                                   Officer and Director

     Pursuant to the requirements of the Securities Act of 1933,
this amendment to Registration Statement has been signed below on
August_4, 1997 by the following persons in the capacities
indicated.


Signature                         Title


/s/ James E. Benson*              Chairman, Chief
James E. Benson                   Executive Officer and Director
                                  (Principal executive officer)

/s/ Ronald J. Carlson             President, Chief Financial
Ronald J. Carlson                 Officer, Secretary and Director
                                  (Principal financial and accounting officer)

/s/ Gary McCarter*                Director
Gary McCarter

/s/ D. Chet McKee*                Director
D. Chet McKee

/s/ Walter Alexander*             Director
Walter Alexander

/s/ Joanne Hansen*                Director
Joanne Hansen

/s/ Marvin Fagel*                 Director
Marvin Fagel

                        Page II-4

/s/ Kenneth Lindgren*             Director
Kenneth Lindgren

/s/ Jesse Maberry*                Director
Jesse Maberry

/s/ William Meyer*                Director
William Meyer

/s/ Alan J. Rassi*                Director
Alan J. Rassi

/s/ Larry Schuster*               Director
Larry Schuster

/s/ William B. Skoglund*          Director
William B. Skoglund

/s/ George Starmann III*          Director
George Starmann III


     Ronald J. Carlson, by signing his name hereto, does sign and
execute this amendment to the Registration Statement on behalf of
the above-named officers and directors of Old Second Bancorp, Inc.
on the day of August 4, 1997, pursuant to the powers of attorney
executed on behalf of each of such officers and directors and
previously filed with the Securities and Exchange Commission.

*By
  /s/ Ronald J. Carlson

      Ronald J. Carlson
      Attorney-in-Fact

                              Page II-5