HLA antigens were identified for 99 Japanese patients with stomach cancer and for 222 controls in Hawaii. There were 68 patients with the intestinal/other histological type of stomach cancer and 31 patients with the diffuse type who may be genetically predisposed towards developing the disease. No significant differences in antigen frequency were noted between cases of the diffuse or intestinal/other histological type and the controls, or between the diffuse and intestinal/other type stomach cancer cases.