A retrospective study of 75 patients with advanced inoperable gastric cancers, referred to the National Cancer Center Hospital between 1962 and 1982, was performed. According to the Borrmann classification based on X ray findings, Type 1 was found in 3 patients, Type 2 in 5, Type 3 in 40, and Type 4 in 15. Twelve patients could not be classified. The histological type was papillary adenocarcinoma in 7 patients, tubular adenocarcinoma in 23, mucinous carcinoma in 6, poorly differentiated adenocarcinoma in 14, signet ring cell carcinoma in 12 and others in 13. The site of remote metastasis in 19 patients was Virchow's lymph node in 8 patients, Douglas pouch in 3, liver and lung in 2 each and others in 4. All patients were treated by a either telecobalt 60 unit or a linear accelerator using 6 Mv photon and the total dose to primary lesion was 4000 cGy in 5 weeks to 7000 cGy in 8-9 weeks. Complete response (CR) was achieved in 6 patients or 8.0%, partial response (PR) in 46 or 61.3%, and no change (NC) in 23 or 30.7%. The response rate based on the sum of CR and PR was about 70%. The 50% survival period in months was 26.5, 7.3, and 3.2, respectively for patients with CR, PR, and NC. For the response of advanced gastric cancer to chemotherapy in the National Cancer Center Hospital, the combined use of UFT and Mitomycin C gave the highest rate, 46%. As for as local response is concerned, the response rate to radiation was 70%, a better result than that of chemotherapy alone.