We report a patient with unresectable gastric cancer who was effectively treated with S-1 after gastrojejunostomy. A 64-year-old man was referred to our hospital for anorexia and epigastric palpable mass. Upper gastrointestinal endoscopy revealed an ulcerous tumor in the antrum of the stomach, and gastric roentgenography showed pyloric stenosis. CT showed simultaneous multiple liver metastases. We performed gastrojejunostomy to allow oral intake. He was treated with daily oral administration of 120-80 mg S-1 for two weeks followed by one week rest as one course. The treatment was repeated for 19 courses until remission was observed. Weekly paclitaxel therapy (80 mg/m(2)/week) was then chosen as second-line chemotherapy. Administration was continued for three weeks with one-week rest. The treatment course was repeated for 6 courses. Bi-weekly administration of CPT-11 (80 mg) and CDDP (30 mg) was chosen as third-line chemotherapy. He died of progressive disease 2 years and 2 months after surgery. During chemotherapy, he maintained a performance status of 0 to 1, and maintained quality of life. This case suggested that the gastrojejunostomy was a useful method for treating unresectable gastric cancer, allowing the possibility of oral intake, and the use of S-1.