We designed a model of peritoneal dissemination of gastric cancer in mice. B16 melanoma cells were injected into the peritoneal cavity of C57 BL mice, the object being to search for an effective treatment for peritoneal dissemination, using hyperthermia combined with cisplatin. Following the intraperitoneal administration of tumor cells, each mouse was subjected to continuous hyperthermic peritoneal perfusion (CHPP) using the peritoneal cavity expander (PCE), with or without cisplatin in the perfusate under conditions of laparotomy. Effects of the therapy were evaluated, based on comparison of survival time between the control and treated groups. There was no prolongation of mean survival periods for the groups given CHPP, with or without cisplatin, compared to findings in the no treatment control group. Optimal timing and doses of hyperthermia and cisplatin, or adding biochemical modulators to enhance the effects of cisplatin, will need to be determined to increase the efficacy of CHPP, with or without the concomitant administration of cisplatin.