At the beginning of his career, Worsley played four years in the minor leagues, most notably for the New York Rovers of the EHL, the St. Paul Saints of the USHL and the Saskatoon Quakers of the WHL. He achieved success with all three teams, garnering First Team All-Star and leading goaltender recognition for three straight seasons between 1950 and 1952.

In the fall of 1952 he was signed by the New York Rangers of the NHL, and though playing for a last place team won the Calder Memorial Trophy as rookie of the year. However, after asking for a $500.00 a year increase in pay, he was promptly returned to the minor leagues for the next year. Playing for the Vancouver Canucks of the WHL, he won the league most valuable player award in 1954.

He again became the starting goaltender for the Rangers in 1954, beating out a then career minor leaguer named Johnny Bower for the position. Wearing the traditional number 1 for goaltenders, he toiled for the oft-hapless Rangers for the next nine seasons, generally playing well for poor teams.

In the summer of 1963, he became involved in a proposed players union, and was promptly traded to the Montreal Canadiens. While he was relegated to the minor-league Quebec Aces for parts of two seasons -- and characteristically winning First Team All-Star honors in the AHL in 1964 -- Worsley played his best years for the Habs, winning four Stanley Cups with the Canadiens in 1965, 1966, 1968 and 1969. His best season was 1968, where he followed up a Vezina-winning performance and a career-low 1.98 goals against average by going undefeated in the playoffs with eleven straight wins. Subsequently, feeling the pressure of performing in Montreal and being phased out in favor of younger goaltenders, he retired in the midst of the 1970 season.

However, Worsley was lured out of retirement by the Minnesota North Stars, and playing in tandem with Cesare Maniago, starred for parts of five more years, retiring at the age of 44. His best season with the North Stars was 1972, where he was second in the league in goals against with 2.12 and was named to play in the All-Star Game.

At the time of his retirement, Worsley had played more games than any goalie except for Terry Sawchuk and Glenn Hall. He retired with a record of 335 wins, 352 losses and 150 ties, with 43 shutouts, and a goals against average of 2.91.

Worsley was inducted into the Hockey Hall of Fame in 1980.

Gump was known for his wry sense of humour and various eccentricities. Early in his career with the Rangers he was once asked, "Which team gives you the most trouble?" His reply?

"The New York Rangers."

He was also vehemently opposed to wearing a mask. He was in fact the second-to-last goaltender to play without a mask. Asked about why he chose to go without he told reporters "My face is my mask."

He was also well known for his fear of flying in airplanes. It is said that when came out of retirement to play for the North Stars he was assured that, as Minnesota was in the central part of the continent, the team traveled less than any other in the league.