The patient was a 76-year-old man having gastric cancer with peritoneal dissemination. He underwent total gastrectomy for resection of the primary tumor and improvement of the oral intake. He developed ileus and peritonitis after the surgery, which necessitated two additional operations. An intestinal stoma was thus therefore created using a catheter for tube feeding, and tube feeding was initiated after the surgery. Nutrients, as well as TS-1 (taken out of the capsule; 80 mg/day) were administered via the catheter for tube feeding. This therapy was followed by a reduction in tumor marker levels and improvement of the patient's performance status (PS), after which the patient could be discharged. He stayed at home for about 8 months, with a much-improved quality of life during this period. We concluded that the TS-1 therapy via the catheter used for alimentation was effective for the treatment of cancer in this patient. We report our experience with this case, in which tube feeding became necessary after total gastrectomy, but administration of TS-1 via the same catheter used for alimentation improved the patient's PS and made it possible for him to receive chemotherapy at home.