An 88-year-old woman, who had undergone distal gastrectomy for Stage IIIA gastric cancer, was diagnosed with recurrent abdominal lymph node metastasis 11 months after surgery. Creatinine clearance of this patient calculated by Cockcroft-Gault method was 44 mL/min and renal function was impaired, so we reduced the administration dosage to 50 mg/day. S-1 was administered for two weeks followed by one week rest. This schedule induced grade 2 anorexia and fatigue after one week administration, so it was converted to one week administration followed by one week rest. By this dosage and administration schedule, a partial response(PR)was continued for about four years without any adverse reaction. This successful case might indicate that it was important for older adult patients with gastric cancer to consider not only appropriate reduction of the dosage but also shortening of S-1 administration.