As a member of the Canadian national junior team at the 1986 World Junior Ice Hockey Championships, Nieuwendyk scored five goals in seven games to help Canada win a silver medal. His 12 points in the tournament tied him for third in scoring for Team Canada and fourth overall in the tournament. One year later, Nieuwendyk joined the senior national team for the Calgary Cup, a four-team exhibition tournament that served as a preview event for the 1988 Winter Olympics. He scored a goal in each of the first two games, losses to the United States and Czechoslovakia, for the Canadian team that won the bronze medal. He joined the senior team again for the 1990 Men's World Ice Hockey Championships, but appeared in only one game after suffering a knee injury. He was invited to Team Canada's summer camp for the 1991 Canada Cup tournament but suffered a knee injury that caused him to miss the entire tournament.