Between 1986 and 1987 patients with hormone refractory metastatic adenocarcinoma of the prostate were treated with hemiskeletal irradiation. One group of 15 patients was treated with a fractionated regimen of 2500-3000 cGy in 9 to 10 fractions. A second group of 14 patients received a single dose of 600 cGy or 800 cGy depending upon whether the upper or lower hemiskeleton was irradiated. Both groups were similar with respect to their initial Karnofsky performance status and extent of disease. With the exception of one patient in the single dose group, all patients treated achieved complete or partial relief shortly after completion of their respective courses of therapy. Of the patients treated with single dose therapy, 10 of 14 (71%) ultimately needed retreatment in the region initially irradiated because of recurrent bone pain or spinal cord compression. In contrast, only 2 of 15 (13%) of the patients receiving the fractionated treatment course needed retreatment (p = .001). Although the median survival of both groups from the time of initial treatments was similar (10 and 11 months), the median duration for palliation was greater for those patients receiving the fractionated regimen as compared with single dose therapy (8.5 months vs 2.8 months). The incidence of treatment related toxicity was similar for both groups. We conclude that fractionated hemiskeletal radiation is a more effective means of palliation when compared to single dose therapy.