MDA Conference Call Alert - September 22, 2005

Richmond, B.C. - MacDonald, Dettwiler and Associates Ltd. (TSX: MDA), a provider of essential information solutions, would like to invite you to join us for a conference call on Thursday, September 22, 2005 at 1:30 pm. PST, 4:30 pm. EST to address any concerns you may have with regard to the potential effect of the Office of Fair Trading report on MDA's property information business in the United Kingdom.

Please find below the information required to join this conference call:

Toll free in North America: 1-866-898-9626

In Toronto: 416-340-2216

About MacDonald, Dettwiler and Associates Ltd. (MDA)

MDA provides advanced information solutions that capture and process vast amounts of data, produce essential information, and improve the decision making and operational performance of business and government organizations worldwide.

Focused on markets and customers with strong repeat business potential, MDA delivers a broad spectrum of earth and space based information solutions, ranging from complex operational systems, to tailored information services, to electronic information products.

MDA employs more than 2,500 people in locations across the United States, Europe, and Canada. The Company's common shares trade on the Toronto Stock Exchange under the symbol TSX:MDA.

Related Websites:
www.mdacorporation.com