Objective: Video games increasingly have become multiplayer, and thus online video game players have the unique opportunity to cooperate with players from all over the world, including those who belong to different social groups. Consistent with research showing that intergroup cooperation leads to reductions in intergroup bias, playing a video game cooperatively with a member of a different social group (i.e., an outgroup member) may reduce bias. The goal of the current study, therefore, was to test whether playing a violent video game cooperatively with an outgroup member reduces intergroup bias toward that partner’s group. Method: In our investigation, Canadians (n = 138) played a violent video game cooperatively with an outgroup (American) or ingroup member against alien (i.e., zombie-like) enemies. Results: Cooperating with an outgroup member in a violent context for only 12 minutes generated large reductions in outgroup prejudice. Conclusions: Our findings highlight the potential for even violent video games to serve as prejudice interventions. (PsycINFO Database Record (c) 2015 APA, all rights reserved)