The currently reported 5-year survival rates for patients with resected stage II, IIIA, IIIB, and IV gastric cancer are 34%, 20%, 8%, and 7%, respectively. A subtotal or total gastrectomy with a D1 en bloc dissection of lymphatic tissue is the standard surgical treatment. Several meta-analyses of post-operative adjuvant trials have reported a significant benefit for chemotherapy-treated patients. Because most relapses occur locally, post-operative adjuvant chemoradiotherapy was studied in patients who received surgery alone or surgery followed by 5-fluorouracil and leucovorin (5-FU/LV, Mayo Clinic regimen) given before, after, and concurrently with radiotherapy in the Intergroup 0116 trial. The 3-year survival and 3-year disease-free survival rates were significantly higher in the adjuvant treatment group, making this regimen the adjuvant standard in the United States. A second trial, the MAGIC trial, also showed improved survival and disease-free survival with epirubicin, cisplatin, and 5-FU (ECF) given every 3 weeks pre- and post-operatively. Other agents in combination with perioperative radiotherapy and surgery are being investigated to treat patients with gastric cancer. New target-oriented agents, as well as tailored therapy based on the molecular profile of both the tumor and the patient, might also contribute to improved results.