Client records spanning a 14-month period were examined for an adolesc
ent unit of a large state psychiatric hospital to identify client vari
ables predictive of acts of physical aggression in hospitalized adoles
cents. Forty-two percent of the 43 girls and 55% of the 57 boys were c
lassified as aggressive because they had committed at least one act of
physical aggression during the data collection period. In logistic re
gression analyses, client characteristics were used to predict aggress
ion classification and 79%, 81%, and 92% of the total sample, girls, a
nd boys, respectively, were correctly classified. Aggression in the gi
rls was associated with having a history of family violence, being of
a minority race, and being on medication; for the boys, aggression was
associated with a diagnosis of a conduct disorder, being on medicatio
n, and being previously hospitalized.