A group of 2978 randomly chosen residents from a rural area of Veneto (Italian region), aged 18-69 years, was assumed as a study population. They underwent US examination of the liver, routine liver function tests, and--when necessary--other imaging techniques and liver biopsy. Liver US exam detected diffuse lesions in 26% of cases (mostly bright liver pattern), and focal lesions in 3%; US findings were normal in 66% of patients and questionable or inconclusive in 5%. As far as focal lesions were concerned, the final diagnosis was angioma (24 cases), cyst (31), neoplasm (5). When bright liver pattern was observed, liver function tests were altered in 78% of the patients; when US findings were normal, liver function tests were normal in 59% of cases. In conclusion our data: 1) show that focal and diffuse liver abnormalities are relatively frequent in unselected and asymptomatic people, 2) confirm US diagnostic utility, and 3) suggest that US be employed as a screening exam in study populations.