Results of previous studies have suggested that transplantation-related mortality among patients with chronic graft-versus-host disease (GVHD) may be reduced by combined treatment with cyclosporine (CSP) and prednisone rather than by prednisone alone. In a randomized trial, we assessed the efficacy of cyclosporine plus prednisone versus prednisone alone as initial therapy for chronic GHVD among patients whose platelet counts were higher than 100,000/microL. Prednisone was administered initially at a dose of 1.0 mg/kg per day orally, followed by a prolonged taper, and cyclosporine was administered at 6 mg/kg orally twice daily every other day. The cumulative incidence of transplantation-related mortality at 5 years from enrollment was 17% (95% CI, 0.11-0.23) in the CSP plus prednisone arm and 13% (95% CI, 0.08-0.19) in the prednisone arm. The hazards of transplantation-related mortality, overall mortality, recurrent malignancy, secondary therapy, and discontinuation of all immunosuppressive therapy were not significantly different between the 2 arms, but survival without recurrent malignancy was lower in the 2-drug arm (P =.03). Avascular necrosis developed in 18 (13%) of the 142 patients in the CSP plus prednisone arm and in 32 (22%) of the 145 patients in the prednisone arm (P =.04). Treatment with CSP plus prednisone may reduce the risk for steroid-related toxicity, but results of the current study do not substantiate the hypothesis that the administration of CSP reduces transplantation-related mortality among patients with chronic GVHD.