Melnyk started his National Hockey League career with the Boston Bruins in 1980. He also played for the Edmonton Oilers, New York Rangers, and Vancouver Canucks. He left the NHL after the 1990 season. Melnyk won 2 Stanley Cup rings with Edmonton, in 1984 and 1985. In 1984, he spent the whole regular season in the minors. He was called up and played six playoff games. His name was not engraved on the Cup, because he had not played enough games to qualify. Melnyk joined Edmonton full-time in 1985, and his name was engraved on the Cup that season.