He was the son of Social Credit politician Oza Tétrault, who was a Member of Parliament from 1968 to 1974.
Tétrault ran as a candidate of the newly formed provincial wing of the Ralliement créditiste in the 1970 election and won, becoming the Member of the National Assembly for the district of Abitibi-Est.
During his term of office, the party was plagued by internal divisions.
Nonetheless, Tétrault and most of his colleagues lost their bid for re-election in the 1973 election.
He finished second against Social Credit candidate Armand Caouette.