The presence of hepatic steatosis was determined in 180 middle-aged male workers by ultrasonography and was found in 39 (22%) of them. Body mass index (BMI), systolic and diastolic blood pressure (BP) and serum levels of asparate aminotransferase (AST), alanine aminotransferase (ALT) and gamma-glutamyl transpeptidase (gamma-GTP) were higher in the subjects with hepatic steatosis. Although the volume of alcohol consumed in a week did not differ between the subjects with and without hepatic steatosis, the hepatic steatosis was thought to relate to both increased body mass and alcohol consumption because the elevations of serum AST and gamma-GTP in the subjects depended largely on alcohol consumption but not on BMI. The results of 75 g oral glucose tolerance test showed a higher blood glucose at 120 minutes and a higher plasma immunoreactive insulin at baseline, 60 and 120 minutes in the subjects with hepatic steatosis, being adjusted for age, BMI and alcohol consumption. The significant association between serum gamma-GTP and BP, which had been often observed in alcohol consumers, was no longer significant after adjustment for plasma insulin levels whereas plasma insulin showed a significant association with BP. These results suggest the possibility that hypertension in alcohol consumers, and also in obese people, relates at least partly to hyperinsulinaemia associated with progression in hepatic steatosis.