Many critics believed Guy Charron was simply not big enough to play hockey in the NHL, which could explain why he was never drafted.
In 1969-70, Charron played 65 games with the Montreal Voltigeurs of the AHL, scoring 37 goals and 82 points. It was that impressive production which caught the attention of the Montreal brass, who called him up to the big team for five games. In 1970-71, Charron was in the lineup for 15 games, where he scored the first two goals of his NHL career. The Canadiens were showcasing his talent, to see if there was any interest amongst other teams for his services. The Detroit Red Wings acquired him midway through the year and in 24 games, scored eight goals and 12 points.
In his first full NHL season with the Red Wings in 1971-72, Charron tallied nine goals and 25 assists, playing primarily a defensive role with the club. During the following two years he was afforded more freedom to play a more wide-open style, resulting in seasons of 18 and 25 goals, respectively.
Charron remained with the Wings until 1974-75, when he was picked by the Kansas City Scouts in the Expansion Draft. He played two years there, scoring 71 points in the 1975-76 season. In 1976-77, Charron joined the Washington Capitals where he posted some of the best offensive numbers of his career. During that first year he scored a career-high 38 goals and 46 assists for 82 points in 80 games, marking the one and only year he averaged better than a point per game. Charron was also a consistent, reliable performer, who did not miss a Capitals' game during his first three years with the team. His last season with the Capitals, and in the NHL, was 1980-81, when he played 47 games. He returned for another two games during a brief comeback with the New haven Nighthawks of the AHL in 1982-83, before retiring as a player.