Sixty-three adolescent suicide victims with a history of affective illness were compared to 23 adolescent community controls with a lifetime history of affective illness, using a case-control design. Suicide victims were more likely to have had major depression, comorbid substance abuse, a past suicide attempt, family history of major depression, treatment with a tricyclic antidepressant, history of legal problems, and a handgun available in the home. There was a non-significant trend for bipolar depression to convey a higher risk for completed suicide than unipolar depression. Recommendations for the prevention of suicide among those with early onset affective illness are discussed in light of these findings.