In a series of 46 patients with localized gastric cancer treated at Massachusetts General Hospital, problems with excessive acute or chronic toxicity due to combination treatment with irradiation (XRT) and chemotherapy (CT) were not seen. Forty of the 46 received combined treatment with 2 regimens: 1) Irradiation plus concomitant 3 days of 5-FU followed by maintenance 5-FU or combined drugs--26 patients; 2) In the other 14 patients, the sequence of irradiation and chemotherapy was altered. A single course of combined drug chemotherapy was given prior to irradiation and 5-6 additional courses were administered after completion of XRT (CT-XRT-CT). The drug combination was initially 5-FU-BCNU but this was changed to FAM (5-FU, Adriamycin, Mitomycin C). Irradiation was delivered to tightly contoured portals using shaped blocks to spare as much small bowel, kidney and marrow as possible while giving 4500-5200 rad in 25 to 29 fractions over 5 to 6 weeks. In this series, there were no cases of septicemia or any deaths related to treatment. A 3 year survival rate of about 20% was achieved for the total group of patients and 43% in the group with resection but at high risk for later failure. Our inability to improve these numbers is undoubtedly a result of dose limitations with external beam irradiation combined with a systemic failure problem. When irradiation is combined with surgical resection of all or a majority of tumor, both survival and local control appear to be better than in the unresected patient group. Only 4 of 29 patients (14%) with curative resection, or resection but residual disease, had later evidence of failure within the irradiation field as opposed to 6 of 9 or 66% in the group with unresectable disease.