Exhibit 23

                 CONSENT OF INDEPENDENT CHARTERED ACCOUNTANTS

We consent to the incorporation by reference in this Annual Report (Form 10-K)
of Cognos Incorporated of our report dated March 28, 2002 (except note 14, as to
which the date is May 24, 2002) with respect to the consolidated financial
statements included in the 2002 Annual Report to Shareholders of Cognos
Incorporated.

Our audits also included the financial statement schedule of Cognos
Incorporated listed in Item 14(a)1. This schedule is the responsibility of the
Corporation's management. Our responsibility is to express an opinion based on
our audits. In our opinion, the financial statement schedule referred to
above, when considered in relation to the basic financial statements taken as
a whole, presents fairly in all material respects the information set forth
therein.

We consent to the incorporation by reference in the Registration Statements
(Forms S-8 No. 33-39562, 33-72402, 33-72404 and 333-8552) pertaining to the 1988
-1993 Stock Option Plan, the 1993-1998 Cognos Employee Stock Purchase Plan (now
the 1993-1999 Cognos Employee Stock Purchase Plan), the 1993-1998 Stock Option
Plan, and the 1997-2002 Stock Option Plan, respectively, of our report dated
March 28, 2002 (except note 14, as to which the date is May 24, 2002) with
respect to the consolidated financial statements of Cognos Incorporated included
in the Annual Report (Form 10-K) for the year ended February 28, 2002.


                                                      /s/ Ernst & Young LLP

Ottawa, Canada                                         ERNST & YOUNG LLP
May 24, 2002                                           Chartered Accountants

                                      120