Alcoholic liver disease (ALD) in Japan was compared clinicopathologically with the occurrence in the U.S.A. ALD found in Japan was more frequently complicated by other hepatic diseases including non-A, non-B chronic hepatitis than ALD found in the U.S.A. (9.9% versus 21.9%). Patients with such complications were excluded from this study. The chief complaints of the total of 51 alcoholics studied in the U.S.A. were abdominal distension or jaundice and those of 98 alcoholics studied in Japan were non-specific: general fatigue, weakness or appetite loss. The U.S. patients exhibited more elevated levels of serum bilirubin (8.1 +/- 7.5 versus 1.9 +/- 2.4 mg/dl, mean +/- SD) and a higher incidence of leukocytosis (49.0% versus 5.1%). While the serum glutamic-oxalacetic transaminase (GOT) levels were not significantly different between the two groups (146.5 +/- 116.8 versus 140.8 +/- 147.7 IU/L), the serum glutamic-pyruvic transaminase (GPT) levels among Japanese alcoholics were higher (38.6 +/- 31.4 versus 87.4 +/- 99.1 IU/L) and in about one quarter of these patients, serum GPT was higher than serum GOT, a feature not seen in the patients in the U.S.A. Comparative histopathologic study of 337 U.S. patients and 210 Japanese patients disclosed a higher frequency of cirrhosis (46.9% versus 33.8%), the presence of Mallory bodies (58.5% versus 13.8%) and marked neutrophilic exudation (45.1% versus 6.2%). Thus, the majority of Japanese alcoholics exhibited progression of liver disease, eventually leading to cirrhosis, due to hepatocellular drop-out and fibrosis caused by a mechanism different from alcoholic hepatitis. In addition, ALD in the U.S.A. revealed more striking extension of fibrosis.(ABSTRACT TRUNCATED AT 250 WORDS)