Peter Mahovlich was known in his playing years as "Little M", as his older brother Frank was the "Big M.", Mahovlich played in the NHL with several clubs, including the Montreal Canadiens, where he played with his brother and was a member of four Stanley Cup championship teams.

He was an important contributor to the Canadiens' cup-winning teams of 1971, 1973, 1976 and 1977. He enjoyed a breakout season in 1970–71, scoring 35 goals in the regular season and another 10 in the playoffs as the Canadiens won the championship. In his 16-year NHL career, he totalled 288 goals and 485 assists for 773 points in 884 games. Internationally, he was a member of the 1972 Summit Series, in which he scored a memorable shorthanded goal in Game 2 of the series.