Among 129 adolescent psychiatric inpatients, four subgroups of suicidal and/or assaultive behaviors were identified. A suicidal-only subgroup with no evidence of assaultive behavior was characterized by depression, drug abuse and environmental stresses. An assaultive-only subgroup with no evidence of suicidal behavior exhibited aggressive symptoms and violence at home. A subgroup with both suicidal and assaultive behaviors experienced accidents and family violence. A fourth subgroup had neither suicidal nor assaultive behavior. This subgroup showed eating disorders, depression, minimal assaultiveness and few peer friendships.