ABSTRACT In open clinical trials that incorporated an ABA design, trazodone was found to be effective in treating aggression in three children (ages 7-9) whose primary diagnoses were disruptive behavior disorders. In two patients, trazodone 75 mg daily was used alone, and in one subject the same dose was used in combination with l-tryptophan 1000 mg daily. At a mean dose of trazodone 0.35 mg/kg daily, significant improvement in aggressive behavior was noted within 7-days. No major problems with side effects were noted, though an increased frequency of penile erections was reported by the 9-year-old during the first week of treatment. Trazodone did not appear to act through its antidepressant or anti-ADHD properties. The efficacy of this selective serotonin reuptake inhibitor in treating aggressive symptoms in children is consistent with previous findings that implicate decreased levels of serotonin in the etiology of aggression.