MDA Initiates Normal Course Issuer Bid

Richmond, B.C. - MacDonald, Dettwiler and Associates Ltd. (the "Company" or "MDA") (TSX: MDA), a provider of essential information solutions, announced today that it has filed a Notice of Intention to make a normal course issuer bid to purchase, subject to regulatory approval, up to 2,000,000 (4.8% of the outstanding Common Shares and 5.7% of the public float) Common Shares from time to time during the next 12 months.

Under the bid, MDA may purchase up to 2,000,000 Common Shares. As of October 26, 2007, there were 41,384,289 Common Shares issued and outstanding. The purchases may begin November 2, 2007 and will end no later than November 1, 2008. The shares will be purchased for cancellation through the facilities of the TSX at market price.

Since all purchases of Common Shares associated with the issuer bid will be made in the open market, the Company is not in a position to know the identity of those from whom it may purchase Common Shares. The Company has purchased 279,900 Common Shares at a weighted average purchase price of $43.30 per share pursuant to its normal course issuer bid that expired October 15, 2007. The average daily trading volume of the Company's common shares on the TSX for the last six months was 205,889.

"We are confident that the continued strength of our cash flow from operations and our substantial credit capacity can support this bid without reducing our ability to pursue attractive growth opportunities," said Daniel Friedmann, President and Chief Executive Officer. To which Anil Wirasekara, Chief Financial Officer added: "The Company believes that the recent market price levels of its Common Shares make the purchase by the Company an attractive and appropriate use of corporate funds in light of potential benefits to remaining shareholders and our commitment to shareholder value".

About 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 3,000 people in locations across the United States, the United Kingdom, and Canada. The Company's common shares trade on the Toronto Stock Exchange under the symbol TSX:MDA.

Related Websites:
www.mdacorporation.com

Forward-Looking Statements

This release contains forward-looking statements and information, which reflect the current view of MacDonald, Dettwiler and Associates Ltd. with respect to future events and financial performance. Any such forward-looking statements are subject to risks and uncertainties and MDA's actual results of operations could differ materially from historical results or current expectations. Additional information on these and other potential factors that could affect MDA's financial results are detailed in documents filed from time to time with the applicable Canadian securities regulatory authorities.

The Toronto Stock Exchange has neither approved nor disapproved the form or content of this release.