In Roberts and Strayer (1996), we reported that emotional expressiveness and anger were important predictors of empathy for school-age children, and that empathy strongly predicted prosocial behaviors aggregated across methods and sources. In this paper, we report how empathy was associated with direct observations of anger and aggression in peer play groups. Twenty-four initially unacquainted five-year-old children (50% girls) were randomly assigned to six same-sex groups; each group met for three one-hour play sessions. Physical and verbal aggression, object struggles and anger were coded from videotapes, as were prosocial and social behaviors. As expected, empathy (aggregated across methods and sources) was negatively associated with aggression and anger, and positively associated with prosocial behaviors. Although children who were more angry were also more aggressive, anger and aggression did not covary across play sessions as a simple causal model requires. These results suggest further directions for research in emotions and aggression.