Gastric cancer sometimes spread to peritoneal surfaces in the absence of lymphatic or hematogenous metastases. For the treatment of peritoneal carcinomatosis, we applied large volume intraperitoneal chemotherapy (L.V.I.C.). In L.V.I.C., drugs were administered with large volume of saline through the reservoir buried in the subcutaneous tissue of the abdominal wall. We used mitomycin C (MMC), 5-fluorouracil (5-FU) and CDDP and examined the pharmacokinetics of these drugs when they were administered by this method to the patients of peritoneal carcinomatosis. A marked pharmacokinetic advantage was observed when 5-FU and CDDP were administered. AUC of these drugs were much larger than that of MMC. In vitro sensitivity test (SDI test) was useful for the selection of adequate drugs for each patient. On this method, drugs were distributed widely in the abdominal cavity and the patients could be taken this treatment repeatedly as out-patient. L.V.I.C. seems to fulfill the need for a safe, effective and acceptable delivery system of intraperitoneal chemotherapy.