In this paper I differentiate among empathy, sympathy and personal distress and discuss the central role of empathy-related responding in positive (including moral) development. Empathy-related responding, especially sympathy, is likely an important source of prosocial, other-oriented motivation. In fact, empathy-related responding, especially sympathy, has been associated with prosocial behaviour (voluntary behaviour intended to benefit another, e.g. helping, sharing); this relation has been obtained for both specific instances of empathy-related responding and for dispositional sympathy. In addition, sympathy (or sometimes empathy) has been linked to relatively high levels of moral reasoning and social competence, and to low levels of aggression and antisocial behaviour. In my talk, I will review research on the relation of empathy-related responding to prosocial behaviour, the consistency of costly prosocial behaviour over time and the possible role of sympathy in its consistency, and the relation of empathy-related responding to moral reasoning, antisocial behaviour and social competence. Examples of research, including longitudinal research in our laboratory, are provided to illustrate these relations. Because of its close relations to social and prosocial responding, an understanding of empathy-related responding contributes to efforts to promote children's moral development.