Previous research suggests that people predisposed toward a more cooperative orientation are stronger at self-control and, accordingly, are better able to ward off the adverse impact of ego depletion on self-regulation (Seeley & Gardner, 2003). Building on this research, we tested the hypothesis that ego depletion would lead to a reduction in concern with the well-being of others among proselfs, but not among prosocials. Study 1 supported the basic proposition that prosocials are higher than proselfs in trait self-control. In Study 2, participants originally classified as prosocials versus proselfs based on mathematical games engaged in an ego depletion task or a control task and later completed a similar measure of prosocial versus proself values. Supporting the primary hypothesis, ego depletion reduced proselfs concern with the well-being of others at time 2, but had no impact among prosocials. Theoretical and practical implications are discussed.