Thirty-seven patients with liver metastases from colorectal cancer were treated with hepatic arterial infusion of 5-FU. Before therapy an arterial access device (Port-A-Cath) was implanted. Treatment was given on an outpatient basis with a portable infusion pump. 5-FU was administered as a continuous infusion at a dose of 1000 mg/sq.m. per day during 5 or 6 days. Cycles were repeated every three weeks. In 12 (37.5%) of the 32 evaluable patients a partial remission was achieved. Median duration of remission was 11 months and median duration of survival was 16 months. Side effects of chemotherapy were usually mild. In 11 patients thrombosis of the hepatic artery was observed, occurring after a median period of 5 months after implantation of the access device. Further study is required to improve the treatment results in this disease with its unfavourable prognosis.