Following his third Stanley Cup victory in 1955, Leswick was traded to the Chicago Black Hawks along with Glen Skov, Johnny Wilson and Benny Woit for Jerry Toppazzini, John McCormack, Dave Creighton and Gord Hollingworth, on May 27. He would score 11 goals and 11 assists in the 1955–56 season for Chicago before jumping to the rival WHL. The Edmonton Flyers welcomed his 53 points in the 1956–57 season and he was invited to another All-Star team. After a brief 22 games for Detroit in 1957, Leswick would again join the Edmonton Flyers until the close of the 1959 season. He would play 9 games the following season for the Vancouver Canucks of the WHL before retiring from playing hockey.