Arrests of American girls for assault and weapons charges are rapidly increasing, at rates exceeding those for boys. Yet research on girls' violence is scant. We surveyed a national sample of 213 girls (ages 9-19) via personal interview or an Internet questionnaire, regarding anger precipitants and behaviors, interpersonal relationships, and experiences of discipline at home and school. Girls were categorized as violent (n = 54) if they had been suspended or expelled from school for fighting or bringing a weapon, or charged with a violent offense by the juvenile justice system. The remaining girls (n = 159) were categorized as nonviolent. The anger of violent girls tended to be intense and generalized, while the anger of nonviolent girls was precipitated by specific situations of injustice. Correlates of feeling angry enough to hit or hurt someone were loneliness, unfair treatment by adults, not liked by classmates, and somatic anger symptoms. Violent girls were significantly more likely to dislike school and perceive school discipline as unfair. Both groups of girls held negative views of television violence and curfews. Although girls with well-established patterns of aggression need psychotherapy, school-based interventions such as emotional literacy and violence prevention programs may also be helpful. Mental health nurses are well prepared to serve in a consultative role to schools, assisting in the development and delivery of violence prevention programming.