This is a case report of the intrahepatic arterial chemotherapy showing an effective reduction of tumors without an operation. The patient was a 68-year-old female. Instead of having an operation to gastric cancer with synchronous hepatic metastases, an intrahepatic arterial embolization of MMC and CPT-11 with DSM was enforced in the right-and-left hepatic arteries, and intrahepatic arterial infusions of 5-FU and CDDP were enforced after that. After intrahepatic infusion, the tumor size and marker of the gastric cancer and synchronous hepatic metastases decreased, and it was diagnosed as partial response (PR). Since the tumor marker showed an increase after thirteen times of the intrahepatic arterial infusions of 5-FU and CDDP, intrahepatic arterial embolization of CPT-11 and MMC with DSM was performed again and the intrahepatic arterial infusions of 5-FU and CDDP were enforced fourteen times after that. Although the tumor marker showed a small range of fluctuation, PR was kept observed and the patient has been stable for fifteen months since the chemotherapy began. She continuously received the combination chemotherapy as an outpatient.