The association between additional co-morbid axis I disorders and the following 28-month course of drinking and mental distress was explored in a nation-wide representative sample (N = 100) of treatment-seeking alcoholics with antisocial personality disorder (ASPD). Diagnoses at admission were assessed with the Diagnostic Interview Schedule and follow-up status was assessed with a questionnaire and from informants. Only 24% had no additional diagnoses, 39% had an affective disorder, 43% panic/agoraphobia, 61% other anxiety disorders, and 47% were polysubstance abusers. Polysubstance abusers had more prior admissions, and were more often involved in fights, while additional anxiety disorder was associated with lower prevalence of drunken driving arrests. Relapse (87%) was best predicted by the number of prior admissions (odds ratio [OR] = 1.3), while affective disorders reduced the risk of relapse (OR = 0.2). Readmissions (55%) were least common among those with affective disorders (44%). Identifying axis I diagnoses, and in particular affective disorders among treatment-seeking ASPD alcoholics, is of substantial importance both in research and clinical practice.