We studied the efficacy of MTX/CDDP/5-FU intra-peritoneal chemotherapy for advanced and metastatic gastric cancer (n=24), and compared the results with intra-aortic (n=26) and intra-venous (n=21) routes of MTX-CDDP-5-FU double modulation therapy. I.p. administration was more efficient for reduction of malignant acites (p=0.049). However, median survival duration of malignant acites cases showed no difference between the i.p. group and i.a., i.v. groups (p=0.103). Survival rate of the i.p. group was no different with those of i.a. and i.v. groups (p=0.36). Frequency of side effects is much lower in the i.p. group.