Cognos to Announce Second Quarter Fiscal 2006 Results on September 21

Ottawa, Ontario and Burlington, Massachusetts, September 6, 2005 - Cognos (Nasdaq: COGN; TSX: CSN), the world leader in business intelligence and corporate performance management (CPM), today announced that it will release second quarter fiscal 2006 financial results on September 21, 2005 after the close of the market. The company will discuss the results on a conference call and Webcast, beginning at 5:15 p.m. Eastern Time.

Listeners can access the conference call at 416-640-1907 or via Webcast at http://www.cognos.com/company/investor/events/fy06q2/index.html. Presentation slides for the call can be accessed at the Investor Relations area of the Cognos Web site approximately 15 minutes prior to the start of the call.

An archive of the Webcast will be available commencing September 21, 2005 at 9:00 p.m. Eastern Time. The archive can be accessed at http://www.cognos.com/company/investor/events/fy06q2/index.html

A replay of the conference call will be available from Wednesday, September 21 at 7:15 p.m. Eastern Time until October 5 at 11:59 p.m. Eastern Time. The replay can be accessed at 416-640-1917. The passcode for the replay is 21150821#.

About Cognos:

Cognos delivers the next level of competitive advantage - Corporate Performance Management (CPM) - achieved through the strategic application of BI on an enterprise scale. Our integrated CPM solution helps customers drive performance through planning; monitor performance through scorecarding; and understand performance through business intelligence.

Cognos serves more than 23,000 customers in over 135 countries. Cognos enterprise business intelligence and performance management solutions and services are also available from more than 3,000 worldwide partners and resellers. For more information, visit the Cognos Web site at http://www.cognos.com.