The Ulm Gallbladder Stone Study is the first ultrasound-based epidemiologic survey of cholecystolithiasis in the former West Germany. A study population of 1116 blood donors (656 men, age 38.0 +/- 12.0 years; 460 women, age 34.1 +/- 11.2 years) at the Central Blood Bank of the German Red Cross in Ulm was examined between April 1994 and February 1995. Based on age, subjects were assigned to one of four groups (18-30, 31-40, 41-50, and 51-65 years). Following a structured interview of each study subject, an ultrasound examination was carried out and a blood sample obtained for laboratory study. Overall, 6.0% (95% (95% CI: 4.8%-7.6%) of all study subjects (5.8% of the men and 6.3% of the women) exhibited evidence of current or past gallbladder disease (cholelithiasis or history of cholecystectomy). The prevalence of gallbladder disease correlated positively with age, reaching a maximum of 13.7% (9.5-20.0) in the 51- to 65-year-old age group, and also correlated as with body mass index (BMI). Female subjects with previous full-term pregnancies showed a higher prevalence of cholelithiasis, but this difference was not statistically significant for age-adjusted analysis. Subjects with a family history of cholelithiasis were found to suffer from gallstones in 11.5% (8.0-16.7) of cases compared with 4.6% (3.4%-6.3%) of subjects without such family history. Autopsy studies conducted in Germany have shown the prevalence of gallstones to be about 13.1% in men and 33.8% in women. Our sonographic data are relatively low in comparison. This may be due, in part, to the specific selection characteristics inherent in retrospective autopsy studies, such as age distribution and the presence of other pathologic factors associated with increased risk for cholelithiasis. The Ulm data rank in the lower third of the prevalence range reported for European sonographic studies to date. Age, positive family history, and increased BMI all correlated positively with the prevalence of gallbladder disease (P < 0.05). For the study population as a whole, there was no gender-specific increased risk for the development of gallstones.