Hepatic metastases of colorectal origin are resistant to radiation and immunotherapy. Traditional intravenous chemotherapy produces responses in 10% to 30% of patients, and surgical resection is feasible in approximately 20% of patients who have a solitary or unilobar lesion. Infusion of cytotoxic agents into the hepatic artery, introduced 2 decades ago, is the most promising form of therapy for unresectable hepatic metastases. Fluorouracil, floxuridine, and mitomycin have been most commonly administered by hepatic arterial infusion. The recent development of a totally implantable pump has allowed prolonged ambulatory infusion of chemotherapeutic agents into the hepatic artery. We review the recent data on the pharmacology, therapeutic outcome, administration techniques, and complications of hepatic arterial chemotherapy. Future trials in this area should use uniform stratification variables and standardized criteria for evaluating response, time to progression, and survival.