The prevalence of gallstone disease (cholelithiasis and previous cholecystectomy for gallstones) in the population of the town of Sirmione, Italy, examined by ultrasonography, was 6.7% in men and 14.6% in women, ranging from 18 to 65 yr of age (overall prevalence = 11%). The prevalence of cholelithiasis in the same age span was 6.9% (4.5% in men and 8.9% in women). Prevalence of cholelithiasis increased with age in both sexes. Twenty-two percent of gallstone subjects suffered from biliary pain vs. 2% of subjects without gallstones. No difference was observed in the frequency of nonspecific symptoms between subjects with and without gallstones. Of the 132 gallstone subjects, 108 (82%) were not aware of having gallstones prior to the study. Prevalence of gallstone disease was found to be higher in obese and hypertriglyceridemic subjects and to increase with the number of pregnancies.