Fifty-seven patients with non-resectable liver metastases (31 from colon cancer, 26 from gastric cancer) received 5-FU, ADR, MMC combined hepatic arterial infusion therapy. (FAMia: 5-FU 334 mg/m2 qw, ADR 20 mg/m2 q4w, MMC 2.7 mg/m2 q2w; in colon cancer, 5-FU 167 mg/m2/day continuously for 3 months and then 334 mg/m2 qw). Myelo-suppression, hepatic arterial occlusion, gastroduodenal toxicity and elevation of biliary enzyme were observed at 29%, 39%, 32% and 13% in colon cancer, respectively, and at 35%, 8%, 0% and 0% in gastric cancer, respectively. Response rates evaluated by CT-scan were 63% (1 CR + 18 PR/30) in colon cancer and 79% (4 CR + 15 PR/24) in gastric cancer. Overall median survival was 352 days in colon cancer and 449 days in gastric cancer. Concerning background factors, the response rate in the well-differentiated type of colon cancer was significantly higher than in the moderately differentiated type, and significantly low in poorly differentiated medullary type gastric cancer. The existence of extra-hepatic lesions was the most important factor in survival in both cancers. [colon cancer: (-) 740 days vs (+) 267 days; gastric cancer: (-) 517 days vs (+) 245 days]. In conclusion, this therapy yields favorable direct effects on liver metastases from colon and gastric cancer without major side-effects and complications, but effective therapy of extrahepatic lesions is required for longer survival. Now, to release colon cancer patients from restrictions of continuous infusion pumps, a phase I study of weekly high dose 5-FU HAI therapy is under way.