Canada's federal election will be held on 2 May.
Prime Minister Stephen Harper made the announcement in the capital, Ottawa, after asking Governor-General David Johnston, Queen Elizabeth's II representative in Canada, to dissolve parliament.
Mr Harper's minority Conservative government was toppled in a confidence vote on Friday.
But he warns voters against choosing a "reckless" coalition to replace it.
After the drama of the vote in the Canadian parliament, and a week of rancorous debate, it was time for the formality of launching an election campaign.
After visiting the governor-general's residence on a snowy Saturday morning in Ottawa, Prime Minister Stephen Harper told reporters that voters had a choice between his party forming a stable majority government in uncertain times, or a what he called a "reckless" opposition coalition.
"You don't try and form a government if you lost the election," he said.
"If Canadians vote for the other party, even by a minority - you respect that judgement."
But the leader of the main opposition Liberal party, the author and historian Michael Ignatieff, ruled out forming a coalition with either of the two smaller opposition parties.
At present his party is trailing in the polls.
And he said in the aftermath of the Conservatives being found in contempt of parliament, the main issues were still trust and accountability.
As the parties put forward the themes they would like to campaign on, Canadians will have the chance to deliver their verdict on 2 May.