The characteristics of adolescent suicide victims (n = 27) were compared with those of a group at high risk for suicide, suicidal psychiatric inpatients (n = 56) who had either seriously considered (n = 18) or actually attempted (n = 38) suicide. The suicide victims and suicidal inpatients showed similarly high rates of affective disorder and family histories of affective disorder, antisocial disorder, and suicide, suggesting that among adolescents there is a continuum of suicidality from ideation to completion. However, four putative risk factors were more prevalent among the suicide victims: (1) diagnosis of bipolar disorder; (2) affective disorder with comorbidity; (3) lack of previous mental health treatment; and (4) availability of firearms in the homes, which taken together accurately classified 81.9% of cases. In addition, suicide completers showed higher suicidal intent than did suicide attempters. These findings suggest a profile of psychiatric patients at high risk for suicide, and the proper identification and treatment of such patients may prevent suicide in high-risk clinical populations.