There have been many studies indicating that increased aggression follows frustration, and that greater frequency or intensity of frustration may result in increased aggression. The imitation of modeling theory of aggression has received relatively consistent support, and imitation of peers and parents has been demonstrated. Additionally, studies have found that direct reinforcement of aggression increases the likelihood of recurrence. Three major dimensions of parenting have been identified as relating to aggression in children: permissive-restrictive, consistent-inconsistent, and affectionate-rejecting. Physiological and biological factors, such as high arousal level, certain neurological and endocrine conditions, and some drugs also increase the likelihood of aggressive violence. Environmental conditions and learning, however, interact with biology and play a crucial role in the development of aggressive behaviors. The treatment and prevention of violence is addressed, and subtypes of violent children are examined. The three most consistent are the socialized-subcultural, the unsocialized-psychopathic, and the disturbed delinquent. Attention is focused on violence in the pediatric setting, and on multidimensional intervention. A case study of a 6-year-old patient who injured three staff members is reported. Included are 94 references.