In general, treatment for gastric cancer with peritoneal dissemination or recurrent gastric cancer is outside the scope of surgery. The efficacy of new anti-cancer drugs such as TS-1 system was revealed in a controlled study by comparing treatment with non-treatment groups. We performed chemotherapy of TS-1 and docetaxel (TXT) in the outpatient clinic on a 72-year-old nonresected gastric cancer patient accompanied by peritoneal dissemination. Although no killer cell effect was recognized, the patient clinically achieved good QOL by this method for one year and seven months. In conclusion, we reported a treatment method for nonresected gastric cancer, which was treated only on an outpatient basis. The course of this case closely resembled the tumor dormancy therapy performed by Takahashi et al.