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                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

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                                    FORM 8-K

                                 CURRENT REPORT

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     Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934


Date of Report (Date of earliest event reported):    AUGUST 21, 1996


                           SONUS PHARMACEUTICALS, INC.
               (Exact name of Registrant as specified in charter)


          DELAWARE                    0-26866                   95-4343413
(State or other jurisdiction        (Commission              (I.R.S. Employer
      of incorporation)             File Number)            Identification No.)


22026 20TH AVENUE, S.E., SUITE 102, BOTHELL, WASHINGTON           98021
        (Address of principal executive offices)                (Zip code)


Registrant's telephone number, including area code:           (206) 487-9500


                                 NOT APPLICABLE
         (Former name or former address, if changed, since last report)
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ITEM 5. OTHER EVENTS

         On July 29, 1996, the Board of Directors of SONUS Pharmaceuticals, Inc.
(the "Corporation") approved the adoption of a Shareholder Rights Plan and on
September 3, 1996 declared a dividend distribution of one Right for each
outstanding share of the Corporation's Common Stock to stockholders of record on
the close of business on August 23, 1996 (the "Dividend Date"). Each Right
entitles the registered holder to purchase from the Corporation a unit
consisting of one one-hundredth of a share (a "Unit") of Series A Junior
Participating Preferred Stock, par value $0.001 per share (the "Preferred
Stock"), at a purchase price of $140 per Unit, subject to adjustment. The
description and terms of the Rights are set forth in a Rights Agreement (the
"Rights Agreement") between the Corporation and U.S. Stock Transfer Corporation,
as Rights Agent.

                  CERTIFICATES. Initially, the Rights will be attached to all
Common Stock certificates representing shares then outstanding, and no separate
Rights Certificates will be distributed. Subject to extension by the Board of
Directors in certain circumstances, the Rights will separate from the Common
Stock and a distribution date (the "Distribution Date") will occur upon the
earlier of (i) 10 days following a public announcement that a person or group of
affiliated or associated persons (an "Acquiring Person") has acquired, or
obtained the right to acquire, beneficial ownership of 15% or more of the
outstanding shares of Common Stock (the "Stock Acquisition Date"); or (ii) 10
business days following the commencement of a tender offer or exchange offer
that would result in a person or group beneficially owning 15% or more of the
outstanding shares of Common Stock. Current 15% stockholders are excluded from
the definition of an Acquiring Person until their respective beneficial
ownership exceeds 30% or more of the outstanding shares of Common Stock. Until
the Distribution Date, (i) the Rights will be evidenced by the Common Stock
certificates and will be transferred with and only with such Common Stock
certificates; (ii) new Common Stock certificates issued will contain a notation
incorporating the Rights Agreement by reference; and (iii) the surrender for
transfer of any certificates for Common Stock outstanding will also constitute
the transfer of the Rights associated with the Common Stock represented by such
certificate.


                  EXPIRATION AND EXERCISE. The Rights are not exercisable until
the Distribution Date and will expire at the close of business on August 23,
2006, unless earlier redeemed by the Corporation as described below.

                  As soon as practicable after the Distribution Date, Rights
Certificates will be mailed to holders of record of the Common Stock as of the
close of business on the Distribution Date and, thereafter, the separate Rights
Certificates will represent the Rights. Except as otherwise determined by the
Board of Directors, only shares of Common Stock issued prior to the Distribution
Date will be issued with Rights.

                  "FLIP-IN". In the event that, at any time following the
Dividend Date, (i) the Corporation is the surviving corporation in a merger with
an Acquiring Person and its Common Stock is not changed or exchanged; (ii) an
Acquiring Person becomes the beneficial owner of more than 15% of the
outstanding shares of Common Stock; (iii) an Acquiring Person engages in one or
more "self-dealing" transactions as set forth in the Rights Agreement; or (iv)
during such time as there is an Acquiring Person, an event occurs which results
in such Acquiring Person's


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ownership interest being increased by more than 1% (e.g., a reverse stock
split), each holder of a Right will thereafter have the right to receive, upon
exercise, Common Stock (or, in certain circumstances, cash, property or other
securities of the Corporation) having a value equal to two times the exercise
price of the Right. Notwithstanding any of the foregoing, following the
occurrence of any of the events set forth in this paragraph, all Rights that
are, or (under certain circumstances specified in the Rights Agreement) were,
beneficially owned by any Acquiring Person will be null and void. However,
Rights are not exercisable following the occurrence of any of the events set
forth above until such time as the Rights are no longer redeemable by the
Corporation as set forth below.

                  For example, at an exercise price of $140 per Right, each
Right not owned by an Acquiring Person (or by certain related parties) following
an event set forth in the preceding paragraph would entitle its holder to
purchase $280 worth of Common Stock (or other consideration, as noted above) for
$140. Assuming that the Common Stock had a per share value of $40 at such time,
the holder of each valid Right would be entitled to purchase 7 shares of Common
Stock for $140.

                  PERMITTED OFFER. A tender or exchange offer for all
outstanding Common Stock at a price and on terms determined by the Board of
Directors prior to the purchase to be adequate and in the best interests of the
Corporation and its stockholders (other than the Acquiring Person) is a
Permitted Offer under the Rights Agreement. A Permitted Offer does not trigger
the exercisability of the Rights.

                  "FLIP-OVER". In the event that, at any time following the
Stock Acquisition Date, (i) the Corporation is acquired in a merger or other
business combination transaction in which the Corporation is not the surviving
corporation; or (ii) 50% or more of the Corporation's assets or earning power is
sold or transferred, each holder of a Right (except Rights which previously have
been voided as set forth above) shall thereafter have the right to receive, upon
exercise, common stock of the acquiring company having a value equal to two
times the exercise price of the Right. The events set forth in this paragraph
and in the third preceding paragraph are referred to as the "Triggering Events."

                  EXCHANGE FEATURE. At any time after any Person becomes an
Acquiring Person and prior to the acquisition by such person or group of 50% or
more of the outstanding Common Stock, the Board of Directors may exchange the
Rights (other than Rights owned by such Person or group which will have become
void), in whole or in part, at an exchange rate of one share of Common Stock (or
a combination of cash, property, Common Stock or other securities having an
equal value) per Right (subject to adjustment).

                  ADJUSTMENT FOR DILUTION. The purchase price payable, and the
number of Units of Preferred Stock or other securities or property issuable upon
exercise of the Rights are subject to adjustment from time to time to prevent
dilution (i) in the event of a stock dividend on, or a subdivision, combination
or reclassification of, the Preferred Stock; (ii) if holders of the Preferred
Stock are granted certain rights or warrants to subscribe for Preferred Stock or
convertible securities at less than the current market price of the Preferred
Stock; or (iii) upon the distribution to holders of the Preferred Stock of
evidences of indebtedness or assets (excluding regular quarterly cash dividends)
or of subscription rights or warrants (other than those referred to above).


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                  With certain exceptions, no adjustment in the purchase price
will be required until cumulative adjustments amount to at least 1% of the
purchase price. No fractional Units will be issued and, in lieu thereof, an
adjustment in cash will be made based on the market price of the Preferred Stock
on the last trading date prior to the date of exercise.

                  REDEMPTION. At any time until ten days following the Stock
Acquisition Date (subject to extension by the Continuing Directors, as defined
below), the Corporation may redeem the Rights in whole, but not in part, at a
price of $.01 per Right. Under certain circumstances set forth in the Rights
Agreement, the decision to redeem shall require the concurrence of a majority of
the Continuing Directors. After the redemption period has expired, the
Corporation's right of redemption may be reinstated if an Acquiring Person
reduces his beneficial ownership to 15% or less of the outstanding shares of the
Common Stock in a transaction or series of transactions not involving the
Corporation. Immediately upon the action of the Board of Directors ordering
redemption of the Rights, with (where required) the concurrence of the
Continuing Directors, the Rights will terminate and the only right of the
holders of Rights will be to receive the $.01 redemption price. Rights are not
exercisable while subject to redemption.

                  CONTINUING DIRECTORS. The term "Continuing Directors" means
any member of the Board of Directors of the Corporation who was a member of the
Board prior to the date of the Rights Agreement, and any person who is
subsequently elected to the Board if such person is recommended or approved by a
majority of the Continuing Directors, but shall not include an Acquiring Person,
or an affiliate or associate of an Acquiring Person, or any representative of
the foregoing entities.

                  STOCKHOLDER RIGHTS. Until a Right is exercised, the holder
thereof, as such, will have no rights as a stockholder of the Corporation,
including, without limitation, the right to vote or to receive dividends. While
the distribution of the Rights will not be taxable to stockholders or to the
Corporation, stockholders may, depending upon the circumstances, recognize
taxable income in the event that the Rights become exercisable for Common Stock
(or other consideration) of the Corporation or for common stock of the acquiring
company as set forth above.

                  AMENDMENTS. Any of the provisions of the Rights Agreement may
be amended by the Board of Directors of the Corporation prior to the
Distribution Date. After the Distribution Date, the provisions of the Rights
Agreement may be amended by the Board (in certain circumstances, with the
concurrence of the Continuing Directors) in order to cure any ambiguity, to make
changes which do not adversely affect the interests of holders of Rights
(excluding the interests of any Acquiring Person), or to shorten or lengthen any
time period under the Rights Agreement; provided, however, that no amendment to
adjust the time period governing redemption shall be made at such time as the
Rights are not redeemable.


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ITEM 7.  FINANCIAL STATEMENTS, PRO FORMA FINANCIAL INFORMATION AND EXHIBITS

         4.1   Rights Agreement, dated as of August 23, 1996 between SONUS
               Pharmaceuticals, Inc. and U.S. Stock Transfer Corporation, which
               includes as Exhibit A thereto a form of Certificate of
               Designation for the Preferred Stock, as Exhibit B thereto the
               Form of Rights Certificate and as Exhibit C thereto a Summary of
               Terms of Shareholder Rights Plan Rights Agreement, dated as of
               August 23, 1996, between SONUS Pharmaceuticals, Inc., a Delaware
               corporation and U.S. Stock Transfer Corporation (incorporated by
               reference to Exhibit 1 to the Company's Registration Statement on
               Form 8-A, dated August 23, 1996).

         20.1  Form of letter to SONUS Pharmaceuticals, Inc. stockholders to be
               dated September 3, 1996.

         99.1  Press Release, dated August 21, 1996.


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                                   SIGNATURES


         Pursuant to the requirements of the Securities Exchange Act of 1934,
the Registrant has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.

                                       SONUS PHARMACEUTICALS, INC.



Date:  August 23, 1996                 By:        /s/ Gregory Sessler
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                                          Gregory Sessler,
                                          Chief Financial Officer


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                                  EXHIBIT INDEX




Exhibit Number     Description
- --------------     -----------
                
     4.1           Rights Agreement, dated as of August 23, 1996 between
                   SONUS Pharmaceuticals, Inc. and U.S. Stock Transfer
                   Corporation, which includes as Exhibit A thereto a form of
                   Certificate of Designation for the Preferred Stock, as
                   Exhibit B thereto the Form of Rights Certificate and as
                   Exhibit C thereto a Summary of Terms of Shareholder Rights
                   Plan (incorporated by reference to Exhibit 1 to the Company's
                   Registration Statement on Form 8-A, dated August 23, 1996).

    20.1           Form of letter to SONUS Pharmaceuticals, Inc. stockholders to
                   be dated September 3, 1996.

    99.1           Press Release, dated August 21, 1996.



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