The conditions of 40 adolescents in treatment following a suicide attempt were diagnosed according to the multiaxial classification of the American Psychiatric Association's proposed third edition of the diagnostic and statistical manual. All were psychiatrically ill before the suicide attempt. The most common diagnoses were those of depressive disorders and substance abuse disorders on the clinical psychiatric syndrome axis and borderline personality disorder on the personality and developmental disorder axis. The typical patient was a polydrug-abusing girl with a borderline personality disorder and a superimposed major depressive disorder. The most prominent personality characteristics associated with suicide attempts by these adolescents were a tendency to react severely to a loss, poorly controlled rage, and impulsivity. Suicide attempts by adolescents should be taken seriously by the physician and necessitate a thorough search for a possible underlying pathological condition.