Purpose/Objective (s): Definitive surgery followed by adjuvant radio chemotherapy has been the standard of care for patients with gastric cancer since the publication of INT0116 study in 2001. This study is to analyze the outcomes of patients with gastric cancer treated with adjuvant radio chemotherapy in Manitoba.Materials/Methods: After definitive surgical resection, patients with Stage IB to IVM0 gastric cancer were treated with fluorouracil (5-FU) and leucovorin. Radiotherapy with concomitant 5-FU was initiated in the second month of the treatment. Radiotherapy, 4500 cGy in 25 fractions, five days per week, was delivered to the tumor bed, the regional nodes, anastomosis, and the residual stomach. All patients were regularly followed. All the sites of recurrent disease were verified by image or biopsy.Results: Between 2002 to 2013, 81 patients, male 61, female 20, aged 38 to 79 years old, who finished a full course of adjuvant radio chemotherapy were identified. The median post-radiotherapy follow up was 57 months (10-196 months). Forty-eight (59.3%) patients survived ≥3 years. Fifteen patients (18.5%) survived ≥5 years, and nineteen patients (23.5%) survived ≥10 years. Eighteen out of 81 (22.2%) patients are still alive with a median survival of 142 months (57-196 months). The tumor and nodal staging, margin status, and lymph vascular invasion are all related to prognosis, but nodal status and lymph vascular invasion in particular were significantly related to prognosis for survival. A prognostic index based on pathologic features has been established to correlate with patient survival with implication for treatment selection.Conclusion: Long-term survival of patients with gastric cancer who received adjuvant radio chemotherapy is possible for a significant portion of patients. A prognostic index has been established to be used for possible risk-based treatment modification.