Laich debuted with Team Canada at the 2003 World Junior Championships, which were held in Halifax, Nova Scotia. In a game against Sweden, Laich scored Canada's first goal of the tournament. He scored two goals and added four assists in six games at the tournament, where Canada won a silver medal. According to his father, Harold, his son had always dreamed of playing for Canada. Laich's next experience with Team Canada came at the 2010 World Championships. He scored one goal in seven games as Canada finished seventh. During the tournament in a game against Russia, Laich raised the ire of his Capitals' teammate Semyon Varlamov for slashing and cross-checking Alexander Ovechkin. Varlamov said of Laich's play, "...Brooks Laich was constantly trying to slash and cross-check him (Ovechkin) as painful [sic] as possible. After the game, he certainly wished me luck and victory at the world championship, but the unpleasant impression still remains."