Hepatic metastases are a major cause of mortality in patients with colorectal carcinoma. The rationale for hepatic arterial chemotherapy has an anatomical and pharmacological basis as presented below. The randomised studies are reviewed and demonstrate a significantly higher response rate with hepatic arterial therapy versus systemic therapy. Survival information is difficult to evaluate because some of the studies are small, and some had a crossover design, but two studies demonstrate a significant improvement in 2-year survival after hepatic arterial therapy compared with systemic therapy. New combinations of 5-fluoro-2-deoxyuridine with dexamethasone and/or leucovorin have produced response rates as high as 72%, median survivals of 22-27 months, and a 2-year survival of 66%. More recent studies on patients who have failed previous systemic chemotherapy have produced response rates around 50%. Hepatic toxicity, especially biliary sclerosis, is the dose limiting toxicity, occurring in 6-25% of patients. To truly define the role of regional therapy, a more accurate randomised study will have to be conducted, to determine if hepatic arterial infusion improves the quality of life and, or survival in patients with hepatic metastases from colorectal cancer.