Smaller than its recent predecessors, the Conservative Cabinet originally consisted of 27 members, including the Prime Minister.

The other two choices that raised some controversy were David Emerson, who was elected as a Liberal, but crossed the floor between the election and the swearing-in of the Cabinet to serve as Minister of International Trade, of the Pacific Gateway, and of the Vancouver-Whistler Olympics, and Michael Fortier, a Montreal-area member of the former Progressive Conservatives and co-chair of the Conservatives' 2006 federal campaign, who was not elected as an MP but was named a Senator on February 27, 2006, and subsequently served as Minister of Public Works and Government Services.

The reason given for the appointments of Emerson and Fortier was that the Conservatives were completely shut out of the three most populous cities in Canada – Montreal, Toronto, and Vancouver.

The Liberals were the only party to win seats in all three, with the Bloc represented in Montreal and the NDP in Toronto and Vancouver.

Contrary to precedent, Harper did not name a Deputy Prime Minister, confounding rumours that Quebec lieutenant Lawrence Cannon or Conservative deputy leader Peter MacKay might be awarded the honorary post.