Information on geographic differences of Epstein-Barr virus (EBV) positivity and association with HLA in gastric carcinoma are limited. Therefore, the association of gastric carcinoma with EBV was examined in 118 patients from Suzhou, China, where the incidence of nasopharyngeal carcinoma (NPC) is high, and in 216 patients from Osaka, Japan, where the incidence of NPC is low, NPC being one of the EBV-associated carcinomas. Expression of HLA-A2 was also examined in some of these cases. The EBV genome was evidenced by PCR and in the tumor cells by in situ hybridization in 7/90 and 9/151 of cases from Suzhou and Osaka, respectively. Immunohistochemistry revealed that cancer cells in all cases with EBV did not express latent membrane protein-I. Type A was found in all cases positive for EBV. Among several histologic and clinical factors, only age of patients showed a correlation with EBV positivity: patients over 60 showed a higher frequency than patients below 60 years of age (p < 0.05). Typing of the HLA-A locus was possible in 16 cases positive for the EBV genome: 3 of 4 cases from Suzhou and 4 of 7 from Osaka were positive for HLA-A2 products. Severe lymphoid cell infiltration was found in 2 of 7 cases and 1 of 4 cases with and without the HLA-A2 type, respectively. The reported frequency of EBV positivity in Chinese living in Taiwan and in Japanese living in Hawaii is higher than in Suzhou, China, and Osaka, Japan, respectively. Our findings suggest that EBV association with gastric carcinoma is influenced by environmental and cultural factors.