Five colorectal cancer patients with nonresectable metastatic liver cancer underwent continuous intraarterial chemotherapy in our institute from January to December 1991. Patients included four rectal cancers and one colonic cancer. 5-fluorouracil (5-FU) was infused continuously through an Infuse-A-Port; 360 mg/m2/day for one week after operation, and 180 mg/m2/day for the following three weeks. Since the fifth week after operation, two weeks without infusion and two weeks of infusion (180 mg/m2/day) were alternated as long as possible. Total periods of 5-FU infusion therapy were from one to 11 months and total doses of 5-FU ranged from 8,750 mg to 25,650 mg. Three patients showed partial response (PR) and two patients progressive disease (PD) (response rate; 60%). In three cases of PR, lengths of infusion therapy and total doses of 5-FU before PR was first observed was 8 weeks, 10,750 mg, 6 weeks, 9,250 mg, and 4 weeks, 8,750 mg, respectively. Four patients presented nausea, appetite loss or abdominal pain, which were considered to be side effects of 5-FU. In one of these four patients, infusion could not be continued because symptoms were so severe. However, catheter troubles were not noticed among all cases.