Mail Stop 4-6

December 27, 2004

Mr. John A. Blaeser
President and Chief Executive Officer
Concord Communications, Inc.
600 Nickerson Road
Marlboro, Massachusetts 01752

Re:	Concord Communications, Inc.
	Post-effective Amendment No. 1 to Registration Statement on
Form
S-3
	Filed December 3, 2004
	File No. 333-112091

Dear Mr. Blaeser:

      This is to advise you that we have limited our review of the
above registration statement to the limited matters addressed in
the
comments below.  No further review of the registration statement
has
been or will be made.  All persons who are by statute responsible
for
the adequacy and accuracy of the registration statement are urged
to
be certain that all information required under the Securities Act
of
1933, as amended (the "Securities Act"), has been included.

      Where indicated, we think you should revise your document in
response to these comments.  If you disagree, we will consider
your
explanation as to why our comment is inapplicable or a revision is
unnecessary.  Please be as detailed as necessary in your
explanation.
In some of our comments, we may ask you to provide us with
supplemental information so we may better understand your
disclosure.
After reviewing this information, we may or may not raise
additional
comments.

      Please understand that the purpose of our review process is
to
assist you in your compliance with the applicable disclosure
requirements and to enhance the overall disclosure in your filing.
We look forward to working with you in these respects.  We welcome
any questions you may have about our comments or any other aspect
of
our review.   Feel free to call us at the telephone numbers listed
at
the end of this letter.

Selling Securityholders

1. Please disclose whether any added selling securityholder is a
registered broker-dealer.  If a selling securityholder is a
registered broker-dealer, please identify such registered broker-
dealer as an underwriter in your disclosure, unless the shares
were
acquired as transaction-based compensation for investment-banking
services.  Provide a description of the investment-banking
services
and the manner in which the compensation for the services was
computed, as applicable.

2. Please disclose whether any added selling securityholder is an
affiliate of a registered broker-dealer.  If a selling
securityholder
is an affiliate of a registered broker-dealer, please expand the
prospectus to indicate whether such selling stockholder acquired
the
securities to be resold in the ordinary course of business.  Also
indicate whether at the time of the acquisition such selling
stockholder had any agreements, understandings or arrangements
with
any other persons, either directly or indirectly, to dispose of
the
securities.

Where You Can Find More Information

3. We note that you filed a Form 8-K on December 2, 2004 prior to
your filing of this post-effective amendment.  Please incorporate
this Form 8-K by reference into your post-effective amendment.
Please refer to Item 12 of Form S-3 for additional guidance.


*              *              *              *

      As appropriate, please amend your registration statement in
response to these comments.  You may wish to provide us with
marked
copies of the amendment to expedite our review.  Please furnish a
cover letter with your amendment that keys your responses to our
comments and provides any requested supplemental information.
Detailed cover letters greatly facilitate our review.  Please
understand that we may have additional comments after reviewing
your
amendment and responses to our comments.

      We urge all persons who are responsible for the accuracy and
adequacy of the disclosure in the filings reviewed by the staff to
be
certain that they have provided all information investors require
for
an informed decision.  Since the company and its management are in
possession of all facts related to your disclosure, they are
responsible for the accuracy and adequacy of the disclosures they
have made.

      Prior to our declaration of the effective date of the
pending
post-effective amendment pursuant to Section 8(c) of the
Securities
Act, the company should furnish a letter acknowledging that:

* should the Commission or the staff, acting pursuant to delegated
authority, declare the filing effective, it does not foreclose the
Commission from taking any action with respect to the filing;
* the action of the Commission or the staff, acting pursuant to
delegated authority, in declaring the filing effective, does not
relieve the company from its full responsibility for the adequacy
and
accuracy of the disclosure in the filing; and
* the company may not assert the staff comments and the
declaration
of effectiveness as a defense in any proceeding initiated by the
Commission or any person under the federal securities laws of the
United States.

      In addition, please be advised that the Division of
Enforcement
has access to all information you provide to the staff of the
Division of Corporation Finance in connection with our review of
your
filing or in response to our comments on your filing.

      You may contact Daniel Lee at (202) 942-1871 with any
questions.  If you need further assistance, you may contact me at
(202) 942-1818 or Barbara Jacobs, Assistant Director, at (202)
942-
1800.

	Sincerely,


	Mark Shuman
	Branch Chief - Legal

cc:	Via Facsimile
	Kevin M. Barry, Esq.
	Andrew Kurzon, Esq.
	Testa, Hurwitz & Thibeault, LLP
	125 High Street
	Boston, Massachusetts 02110
	Telephone: (617) 248-7000
	Facsimile:  (617) 248-7100