The positive results recently reported by the Intergroup 0116 Study with adjuvant chemoradiation have stimulated an increasing interest in the combined modality treatment of gastric cancer. The significant improvement in disease-free and overall survival reported in this study was related mainly to an improvement in local control rather than to a decrease in the incidence of metastatic disease. Therefore, new and potentially more effective chemotherapy regimens could be considered and the feasibility of their integration with radiation therapy needs to be explored to further improve the treatment in gastric cancer. Our experience with combined radiation therapy and 5-FU-with or without 5-FU based chemotherapy--in unresectable and in partially or radically resected gastric cancer is retrospectively reviewed. In addition, an initial prospective evaluation of the feasibility and toxicity of radiation and 5-FU following adjuvant chemotherapy with modern platinum containing regimens is reported. Our data and the current available experiences with investigational approaches in gastric cancer involving preoperative chemotherapy and intraoperative radiotherapy will be considered in exploring a new combined modality treatment program.