Lemieux played junior hockey for the Thetford Mines Canadiens and the Montreal Junior Canadiens. He won the Memorial Cup in 1969 and 1970 with Montreal. The Vancouver Canucks chose him 39th overall in the 1971 NHL Amateur Draft. He scored 52 points in 1972-73 with the Canucks but dropped to 22 the next season. The Kansas City Scouts picked him up in the 1974 NHL Expansion Draft and he scored 30 points for them in 1974-75. In the NHL Lemieux played in 274 games and scored 39 goals and 82 assists. In the WHA he played in 33 games and scored 6 goals and 11 assists.