One hundred sixty-eight patients with primary affective disorder were studied regarding history of alcohol-related problems. Alcohol-related problems were identified in 19 patients. We found that the morbid risk for alcoholism was significantly increased among relatives of male patients with drinking problems as compared to relatives of male patients without drinking problems. Our data suggest that psychiatric illness in relatives of probands with severe bipolar illness tends to be affective disorder tends to include alcoholism plus affective disorder.