Cancers of the esophagus, gastroesophageal junction (including the gastric cardia), and stomach represent three separate diseases with marked epidemiologic variations. The Department of Veterans Affairs computerized database records the ethnicity of all hospitalized patients throughout the United States, which provides an opportunity to study the influence of ethnicity on cancer rates in a uniform health-care system. All hospitalized patients, from 1980 through 1995, with a diagnosis of upper gastrointestinal cancer were identified. For each ethnic group and cancer type, hospitalization was expressed as an age-adjusted proportional rate per 10,000 hospitalizations from all causes. Hospitalization with gastric cancer was most frequent among Asians (48.4 per 10,000 hospitalizations) followed by blacks (33.3), Hispanics (28.7), American Indians (20.3), and whites (12.0). Adenocarcinoma of the gastroesophageal junction accounted for 5.9 per 10,000 hospitalizations among Asians, 4.5 among whites, and 4.5 among Hispanics. Gastroesophageal junction cancer was lowest among blacks (2.9) and American Indians (2.4). Finally, squamous cell carcinoma of the esophagus was frequent among blacks, 68.2 per 10,000, followed by Hispanics (36.4) and Asians (27.8), and was low among whites 24.0 and American Indians (21.5). Esophageal cancer rates remained stable in all ethnic groups from 1980 through 1995; gastroesophageal junction cancer rates increased particularly among whites, whereas gastric cancer rates declined in whites and blacks but not in Hispanics. There were significant ethnic differences in the occurrence of gastroesophageal malignancies among US military veterans. Environmental factors may explain some of these differences. Differential rates of Helicobacter pylori infection with resultant gastric atrophy and reduced acid output led to a greater risk for gastric cancer, but a reduced risk for reflux disease and cardiac cancer.