48 patients with colorectal cancer metastatic to the liver were implanted with a subcutaneous access system allowing hepatic intra-arterial perfusion. Regional chemotherapy used 5-fluorouracil, while 17 patients also received low-dose mitomycin at the beginning of the study. Responses to the treatment occurred in 29 patients (60%) and median survival was 14.4 months. Toxicity included gastroduodenal erosions in 12.5% of the patients, leucopenia in 20.8%, catheter thrombosis in 42% and arterial thrombosis in 50%. 2 patients died of digestive haemorrhage probably related to treatment. When individually analysed, four factors were found to significantly affect survival: presence of hepatomegaly (defined as palpable liver edge exceeding the right costal margin by more than 5 cm) (P = 0.006), percentage of hepatic replacement superior to 50% (P = 0.003), more than four metastases (P = 0.025) and hypovascularised metastases at radionuclide liver scan with 99m technetium-labelled macroaggregate albumin (MAA) (P = 0.04). The effect of the four variables on the observed survival time was analysed using a Cox regression model. Two variables were found to have simultaneously influenced survival. Presence of hepatomegaly emerged as the more significant (P = 0.0001), the other being hypovascularised metastases at 99mTc-MAA.