The patient was a 66-year-old male, admitted and diagnosed as having advanced gastric cancer with peritoneal dissemination, leading to ascites and obstructive jaundice. After reducing the degree of obstructive jaundice, combination chemotherapy of S-1 80mg/m2/day(2 weeks administration and 1 week rest)and docetaxel(TXT)40mg/m2(day 1)was administered from February, 2008. After 3 courses of this regimen, CT revealed no evidence of ascites, and this chemotherapy was successively continued on an outpatient basis until June, 2009. After the relapse of ascites from July, 2009, combination chemotherapy of irinotecan(CPT-11)60mg/m2 and cisplatin(CDDP)30mg/m2 biweekly was performed as second-line chemotherapy, and the ascites disappeared again after around 2 courses of this regimen. This chemotherapy was continued on an outpatient basis until February, 2010. No major adverse reaction to either chemotherapy was observed. This case suggests that these chemotherapies, such as the combination chemotherapy of S-1 plus TXT as a first-line treatment and CPT-11 plus CDDP as the following second-line treatment, can be administered to an outpatient, can keep good patient's QOL and can be one of the effective chemotherapy options for advanced gastric cancer with peritoneal dissemination.