There has been recent emphasis on the importance of investigating prosocial and antisocial behavior simultaneously owing to doubts about whether examining one automatically gives information about the other. However, there has been little empirical research into this question. The present study (based on a large population sample of preadolescents, N = 2,230) simultaneously examines prosocial and antisocial behavior, explicitly including the possibility that children might show prosocial behavior according to one informant and antisocial behavior according to another. When parents and teachers agreed in their judgments, children were distinctly profiled and differed clearly in effortful control, intelligence, academic performance, and several peer nominations and family characteristics. The correlates were more rater-specific for children that were prosocial according to one informant and antisocial according to the other informant. Teachers and parents used different context-dependent criteria for judging children to be prosocial or antisocial. Academic performance and peer relations were related to the teacher's judgment of prosocial and antisocial behavior. By contrast, children's being problematic at home (and thus causing stress for the parents) was related to the parents' judgment.