Nilsson began his career during the season of 1973–74, playing for
Djurgårdens IF during his first of four seasons in Sweden. He then came to North America, and played for the
Winnipeg Jets of the
World Hockey Association (WHA) beginning in
1977. He scored two consecutive 100-point seasons in the WHA. He was claimed by the
Atlanta Flames, and in his first season with the team he scored 93 points. The next season,
1980–81, the Flames moved to
Calgary; Nilsson scored 131 points. Nilsson played with the Flames, wearing number 14, until
1984–85 when he was traded to the
Minnesota North Stars for a draft pick that the Flames used to draft
Joe Nieuwendyk. Nilsson won his first and only
Stanley Cup while playing with the
Edmonton Oilers in
1987. He returned to Europe after that season, playing in Italy, Switzerland, Sweden, Austria, and Norway. In 1988–89, he was named player-of-the-year in Sweden. He returned to Edmonton for six games in
1995, which made him the last former Atlanta Flames player to play in the NHL. He then played the remainder of his playing career in Switzerland, Sweden, Norway, Austria, Germany until 1998 when he last played in the
Spanish hockey league for
SAD Majadahonda in six games, making Nilsson one of the few former Stanley Cup winners to play in the league. Nilsson holds the NHL record for the quickest goal scored during a season-opening game, at ten seconds in, while playing for the North Stars versus the
Quebec Nordiques on 11 October 1986. ==Awards==