A male patient in his 60s at the time of the first medical examination had a smoking history of 50 years with 25 cigarettes a day. He was diagnosed with double urothelial cancers. In 200a, total left pelvic ureterectomy(pT2N0M0, Stage Ⅱ)and transurethral bladder tumorectomy(pTisN0M0, Stage Ⅰ)were performed. For his gastric cancer with malignant pleural effusion(cT3N0M1, Stage Ⅳb), in 200a plus 2, downstaging was acquired after chemotherapy. In 200a plus 5, subtotal gastrectomy D1 dissection was performed(W/D adenocarcinoma, pT2N0M0, Stage ⅠA, Ef 1). For the first lung cancer, in 200a plus 5, thoracoscopic lung wedge resection of the left lower lobe was performed(P/D adenocarcinoma, pT1aN0M0, Stage ⅠA1, R0, Ef 1). For the second lung cancer, in 200a plus 13, thoracoscopic lung wedge resection of the right upper lobe was performed after chemotherapy(P/D adenocarcinoma, pT1bN0M0, Stage ⅠA2, R0). For the third lung cancer, in 200a plus 17, immunotherapy was performed for the left upper lobe lung cancer(P/D adenocarcinoma, cT3N1M1a, Stage ⅢA). All the cancers were diagnosed as primary lesions by immunohistological examination. For the metachronous multiple cancers, multidisciplinary treatment was necessary for each cancer considering the patient's physical condition. Moreover, strict follow-up was necessary because of the high risk of carcinogenesis.