A 54-year-old woman was admitted to our hospital with elevated creatine phosphokinase (3537U/ L) and muscle weakness of the lower limbs without any cutaneous lesions. Therefore, we diagnosed polymyositis. Upper gastrointestinal endoscopy and computed tomographic scan revealed a Borrmann type III tumor on the lower body of the stomach. We performed laparoscopic distal gastrectomy. Two years after the distal gastrectomy, early remnant gastric cancer was found and we performed total remnant gastrectomy. In situ hybridization against EBVencoded small RNA 1 revealed that most of the cancer cells of both tumors were Epstein-Barr virus positive.