Understanding the links between anger expression by children and adolescents, their health, and their interpersonal interactions is important given the evidence that anger is associated with maladjustment and illness among adults. This review covers: 1) possible origins of the awareness and expression of anger; 2) assessment of anger in children and adolescents, including both self-report and observational approaches; 3) implications of anger expression for interpersonal relationships; and 4) outcomes of anger expression. Dimensions of anger expression found in adults have been corroborated to some extent in child and adolescent data. Reliable and valid measures of these dimensions have been developed. There has been much less research on the correlates of maladaptive anger expression in children or adolescents than in adults. Nevertheless, the current data base provides some confirmation that youth who cope inappropriately with their anger are at risk for problematic interpersonal relationships and negative outcomes in terms of both mental and general health.