Twenty-three patients with colo-rectal hepatic metastases were retrospectively reviewed after completing treatment with split course liver irradiation and continually infused concomitant intravenous 5-fluorouracil. Although no patient attained a complete response, an objective partial response was documented in 15 (Responders). The Responders had a median survival of 45 weeks whereas Non-responders had a median survival of 17 weeks. Patients with metastatic disease solely in the liver or those with a Karnofsky performance score (k.p.s) of over sixty, had a median survival of 49 weeks. Patients with multiple organ metastatic involvement had a median survival of 25 weeks and those with a Karnofsky with less than 60 had a median survival of 27 weeks. (p values of 0.006 and 0.03, respectively.) The overall survival of the group completing treatment was 30 weeks, and 19 patients (83%) achieved subjective palliation. The patients tolerated therapy well. There was minimal hematological toxicity; 3 patients developed a leucocyte count of less than 2000 and 1 developed a platelet count of 30,000. The palliation and prolongation of survival attained with minimal complications suggest that adjuvant liver irradiation with concomitant infusion 5-fluorouracil radiosensitization may be an option to offer patients identified to be at high risk of developing subclinical liver disease.