Mail Stop 4561

      February 9, 2006

Tom Manley
Senior Vice President, Finance & Administration
and Chief Financial Officer
Cognos Inc.
3755 Riverside Drive
P.O. Box 9707, Station T
Ottawa, ON Canada  K1G 4K9

	Re:	Cognos Inc.
   Form 10-K for the Fiscal Year Ended
   February 28, 2005
		Filed April 29, 2005
		File No. 033-72402

Dear Mr. Manley:

	We have reviewed your response to our letter dated January 6,
2006 in connection with our review of the above referenced filings
and have the following comments.  Please note that we have limited
our review to the matters addressed in the comments below.  We may
ask you to provide us with supplemental information so we may
better
understand your disclosure.  Please be as detailed as necessary in
your explanation.  After reviewing this information, we may 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.

Form 10-K For the Fiscal Year Ended February 28, 2005

Critical Accounting Estimates, page 44

1. We note your response to our previous comment no. 1 and the
information provided in Appendix A to such response.  With regards
to
this information, please provide the following:
* In response to our comment no. 2 in your letter dated December
5,
2005, you indicate that for arrangements in which product support
is
a named element of an arrangement but is not separately negotiated
as
part of the order agreement and no renewal rate is stipulated
within
the agreement, the Company allocates a portion of the arrangement
fee
to product support based on a percentage of the license fee.  Tell
us
which percentage, as provided in Appendix A, is used as VSOE for
such
contracts (i.e. the low end, the high end or the median).  Also,
tell
us how you determined that the ranges for each class of customer
are
representative of VSOE for product support when contracts do not
include a stated renewal rate.  For instance, how did you evaluate
the percentage of contracts that fall within the low and high end
of
the range and how did you evaluate the deviation from the median
point of the ranges to determine that such ranges are sufficiently
clustered to conclude that VSOE of fair value exists for each
class
of customer as defined in your response.
* You indicate that the analysis does not account for software
licenses that have an aggregate license value of $50,000 or less.
We
note the median and average product support renewal percentage
indicated in your response.  Tell us what portion of the customers
fall within this range.


      * * * * *

      As appropriate, please amend your filing and respond to
these
comments within 10 business days or tell us when you will provide
us
with a response.  Please submit all correspondence and
supplemental
materials on EDGAR as required by Rule 101 of Regulation S-T.  You
may wish to provide us with marked copies of any amendment to
expedite our review.  Please furnish a cover letter with any
amendment that keys your responses to our comments and provides
any
requested information.  Detailed cover letters greatly facilitate
our
review.  Please understand that we may have additional comments
after
reviewing any amendment and your responses to our comments.

	 You may contact Patrick Gilmore at (202) 551-3406 or me at
(202) 551-3730 if you have questions regarding comments on the
financial statements and related matters.

							Sincerely,


							Kathleen Collins
							Accounting Branch Chief

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Tom Manley
Cognos Inc.
February 9, 2006
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