The 1982-1984 Hispanic Health and Nutrition Examination Survey used ultrasonography to investigate the epidemiology of gallstone disease. Mexican American, Cuban American, and Puerto Rican men and women, aged 20-74 yr, were selected from household samples in Texas, New Mexico, Arizona, Colorado, California, Connecticut, New Jersey, New York, and Florida. Ultrasonography was performed on 2299 persons. The age-adjusted prevalence of gallstone disease (gallstones + cholecystectomy) among Mexican American men (7.2%) was 1.7 times that of Cuban American men and 1.8 times that of Puerto Rican men. The prevalence for Mexican American women (23.2%) was 1.5 times that of Cuban American women and 1.7 times that of Puerto Rican women. Rates were about three times higher among women than men and increased with age in both sexes and all ethnic groups except older Puerto Rican women. Among Mexican American women aged 60-74 yr, the prevalence of gallstone disease reached 44.1%. These results support the hypothesis that Mexican Americans are at increased risk of gallstone disease.