To clarify the prevalence of gallstone disease in Bolivia, all the X-ray films of the biliary system in a total of 656 cases taken during 10 months in La Paz were checked. Gallstones were found in 103 cases (15.7%). The ratio of male to female was 1:1.9. Cholecystolithiasis comprised 76.7% of them, while choledocholithiasis was rare. The analysis of gallstones removed surgically by an infrared absorption spectroscopy revealed that cholesterol was main constituent of stones in 62 cases (93.9%) out of 66 cases.