Experimental games like the dictator game have proven of great value for the study of altruism and sharing behavior. It has been shown that individuals differ substantially in the amount of money they offer to an anonymous receiver. Yet, to date little is known about how personality dispositions shape differences in altruistic sharing. The current study aimed at elucidating the effects of affective empathy in comparison to cognitive empathy and the disposition of justice sensitivity on altruistic sharing in the dictator game. Different aspects of these constructs were assessed multi-methodologically in young adults and related to their offers in the dictator game. Analyses revealed that affective empathy and justice sensitivity explain altruistic sharing behavior, but different dimensions of cognitive empathy do not. The results support the assumption that affective reaction tendencies explain differences in altruistic sharing. (Contains 3 tables and 2 figures.)