For the purpose of improving operability and curability, we performed intraarterial infusion chemotherapy on four patients with advanced gastric cancer diagnosed pathologically as papillary adenocarcinoma or poorly differentiated adenocarcinoma. Anti-cancer drugs including cis-diamminedichloroplatinum (II), epirubicin, and mitomycin C were administered through catheters whose tips were placed at various sites, as follows: celiac artery, common hepatic artery, right and left gastric artery, accessory left gastric artery, gastroduodenal artery, and right gastroepiploic artery. The therapeutic effect was evaluated by computed tomography (CT) and double contrast X-ray examination of the stomach. A partial response was obtained in one patient, there was no change in two patients, and the fourth patient showed no change and died eight months later. One patient had no recurrence, and recurrence was found in two. The major toxicity was bone marrow suppression, and other side effects such as appetite loss, nausea, and vomiting were all transient. A deep gastric ulcer was found in one patient, but it was cured by intravenous administration of H2 blocker. Although the four patients showed varying responses, intraarterial chemotherapy may prove to be an assistant therapy that enhances the therapeutic effect.