Walter was drafted second overall by the Washington Capitals in the 1978 NHL Amateur Draft. At the time the Capitals named him as team captain in his second season, he was the youngest player in the history of the NHL to hold that position. Walter was traded to the Montreal Canadiens in a blockbuster trade in 1982. He went to Montreal along with Rick Green in exchange for Doug Jarvis, Rod Langway, Craig Laughlin and Brian Engblom. Walter's name is engraved on the Stanley Cup, which the Canadiens won in 1986 though Walter was injured for most of the playoffs. In the 1989 Stanley Cup Finals, he scored in the second overtime period of game three to give the Canadiens a 2–1 series lead. However, the Calgary Flames came back to win the series and the Cup. In 1991, he signed as a free agent with the Vancouver Canucks, where he played the final two seasons of his career and won the Budweiser NHL Man of the Year Award in 1992. He was known as a tough, hard-working player who was excellent in the face-off circle. Walter also served as vice president of the NHLPA.
On June 17, 2008, Walter was named an assistant coach to Alain Vigneault of the Vancouver Canucks. He was relieved of his duties after the 2009-10 season. On September 21, 2010, Walter was named head coach of Canada's women's hockey team which won the gold medal at the 2010 Four Nations Cup.
Front office
Walter served as the president of the Abbotsford Heat of the American Hockey League, which is the minor-league affiliate of the Calgary Flames from 2011 to 2014.
Personal life
Walter is a motivational speaker, author and leadership expert, using his experiences in hockey to relate to business and success. Walter also had a cameo appearance in the movie Miracle, playing the referee in the game between the USA and USSR in Lake Placid and was hired by Disney to be a hockey expert for the movie. He was also hired as a hockey expert for both seasons of , a Nike hockey commercial, and played himself on an episode of the Canadian animated television seriesBeing Ian. Walter has three sons who are also hockey players. His oldest son, Ben, was drafted by the Boston Bruins and played 24 games in the NHL. Joey played with the Langley Chiefs of the BCHL and the Trinity Western University Spartans, and his other son, Ryan Jr., played for the TWU Titans in 2006-07 and 2007–08 as well as the Liberty University club hockey team.