The histologic appearances characteristic of chronic active hepatitis (CAH) were observed in liver biopsies of seven patients among whom alcohol abuse was the only identifiable determinant of liver disease. Clinical, hematologic, biochemical and histologic features in these patients were contrasted with those of 20 patients with typical alcoholic hepatitis. For the CAH group, the liver was less enlarged below the costal margin, a palpable spleen was more frequent, the mean neutrophil count was lower, and there was a lower mean level of transaminase enzymes. In both groups there was minimal evidence of the serologic markers of autoimmune CAH or antecedent hepatitis B virus (HBV) infection. Histologically, all liver biopsies in the CAH group showed perilobular "piecemeal" necrosis, "rosette" formation and dense portal and septal lymphoid infiltrates, in contrast to the fatty change, Mallory bodies and intralobular neutrophil clusters of the alcoholic hepatitis group. In the CAH group, a second liver biopsy was assessed after a period during which alcohol consumption was known; histologic improvement or deterioration correlated with abstinence or continuation of drinking. Thus "alcoholic" CAH has some clinical and histologic features distinct from those of typical alcoholic hepatitis, but the two types were similar in other respects including dependence of the course of disease on continuing use of alcohol.