This study presents personality and biochemical correlates to abusive and suicidal behavior in 49 male alcoholics. Our hypothesis was that neuroendocrine and personality characteristics reflect a postulated regulatory mechanism that determines the direction of aggression either outward (abusive) or inward (suicidal). Eleven patients (22%) had physically abused someone on one occasion and 15 (31%) constituted a more violent subgroup with repeated instances of abuse. Thirteen (27%) had attempted suicide at least once. There was a significant positive correlation between the number of abusive and suicidal events (r = 0.33). The violent subgroup with repeated episodes of physical abuse had elevated levels of serum testosterone and low levels of cortisol when compared with the rest of the sample. Aggressive, antisocial, and impulsive personality traits were common. Suicidal alcoholics did not differ from the rest regarding hormone levels, but exhibited high impulsivity and muscular tension on the personality test. It is suggested that the high impulsivity without aggressive traits makes them exhibit autoagressive rather than abusive behavior. Both the abusive and suicidal alcoholics partly had a history typical of the type 2 alcoholic. We propose that these two categories constitute subgroups of the type 2 alcoholic determined by a combination of genetic predisposition to alcoholism, certain personality traits, and, with regard to the violent group, also hormone disturbances. We find it highly justified to identify and treat these subgroups because of their harmful acting-out behavior.