Fifty-six patients with bilateral sight-threatening noninfectious intermediate or posterior uveitis participated in a randomized double-masked study of the use of cyclosporine vs prednisolone in their treatment. Applying the end-point definitions, visual acuity or vitreal haze improved in only 13 of 28 (46%) patients in each group. The macular edema resolved in seven of 15 patients of the cyclosporine-treated group, and in ten of 16 patients of the prednisolone-treated group (P = .376). Patients whose therapies failed both cyclosporine and prednisolone trials were treated with both drugs, which resulted in additional patient improvements. Secondary effects were observed in both therapeutic alternatives, the most notable being alterations in serum creatinine concentration and hypertension with the dosage of cyclosporine used.