We use data from a street football tournament and a series of lab-in-field experiments in postconflict Sierra Leone to examine the impact of exposure to conflict violence on competitive behavior. We find that football players who experienced more intense exposure to violence are more likely to get a foul card during a game. In the lab we find that these individuals are significantly less risk averse and more altruistic toward their in-group (teammates). We then isolate competitiveness from aggressiveness and find that conflict exposure increases the willingness to compete toward the out-group. These results are in line with theory highlighting the role of intergroup conflict in increasing in-group cooperation while exacerbating out-group antagonism. Next to other-regarding preferences and risk propensity, changes in individual preferences for competition may affect long-run development trajectories and postconflict recovery.