Gilbert began his NHL in the 1969-70 season with the Minnesota North Stars. He would go on to play in four seasons for the North Stars before moving on to the Boston Bruins, where he'd spend the next seven seasons. Gilbert would then finish his career off by playing three seasons with the Detroit Red Wings.
In 416 games in the National Hockey League, Gilbert had 192 wins, 143 losses, 60 ties, a goals against average of 3.27, an .872 save percentage and 18 shutouts.