When the Stingers folded in the WHA-NHL merger, in 1979, Hislop's rights were acquired by the Winnipeg Jets, who traded him a few days later to the Quebec Nordiques for defenseman Barry Melrose. He was the only player to play in all 80 games for the Nordiques during their inaugural season in the NHL, scoring 19 goals. In 1980, he had the good fortune of being inserted as the right winger on a line with brothers Peter Stastny and Anton Stastny, and after a short period of adaptation, the three clicked beautifully together as Hislop scored 41 points in 50 games. With Réal Cloutier, another right-winger, back from an injury and the Nordiques weak in goal, he was traded midway through the season to the Calgary Flames in exchange for Dan Bouchard; it proved to be his best year in the NHL with a combined 25 goals and 31 assists for 56 points. He played the remainder of his career with the Flames, settling into being a solid two-way player who almost never missed a game and serving two full seasons before an eye injury sustained in a game against the New York Islanders on December 1, 1983 forced his retirement.