The aim of the present study was to determine the prevalence of biliary lithiasis (BL) and its major associated factors in the elderly people of a small town in Sicily. All inhabitants over the age of 65 were interviewed and underwent a general physical examination, blood tests and ultrasonography of the gallbladder and biliary tracts. The final group included 328 subjects (162 men and 166 women), representing 63.1% of the population asked to participate, with a mean age of 74.3 +/- 6.8 years (range 65-95). The prevalence of BL (lithiasis in progress + subjects cholecystectomized for previous calculosis) was 18.6%. No male subject had been cholecystectomized. Prevalence was higher in women than in men, but there was no progressive increase with age. There was no significant correlation between number of pregnancies and BL and there was no statistically significant difference between subjects with and without lithiasis for total cholesterol, triglycerides, HDL-cholesterol, A-I and B apoprotein values; a significant difference was found only for body weight values (p less than 0.01). Stones were more often multiple and more radiopaque than in younger subjects; specific symptoms and positive family histories were found in 22% and 18% of the study group, respectively.