The aims of this study were to examine whether certain axis I disorders characterized by impulsive aggression were associated with self-mutilative behavior and to evaluate the clinical correlates of self-mutilation in a sample of general psychiatric outpatients. Two hundred fifty-six outpatients were administered diagnostic interviews for axis I and axis II disorders. In addition, questionnaires that measured self-mutilative acts within the last 3 months, dissociation, and childhood abuse were completed. This study found that axis I disorders of substance abuse, posttraumatic stress disorder, and intermittent explosive disorder were significantly related to self-mutilative behavior, independent of borderline personality disorder and antisocial personality disorder. Also, a higher level of dissociation was related to self-mutilation, controlling for borderline personality disorder and childhood abuse. Outpatients with certain axis I disorders and those who dissociate may represent a sizable group of patients who are at risk for self-mutilative behavior.