 He was first elected at the Victoria riding in the 1963 general election, after previous defeats at the Esquimalt—Saanich riding in the 1962 election and in a 29 May 1961 by-election.Groos was re-elected at Victoria in the 1965 and 1968 elections.After finishing his term in the 28th Canadian Parliament, he was defeated by Allan McKinnon of the Progressive Conservative party in the 1972 federal election.