The results are presented of a double-blind trial comparing the efficacy of betamethasone phosphate 0.1 per cent, clobetasone butyrate 0.1 per cent, and placebo in the treatment of acute unilateral non-granulomatous uveitis. The two steroids gave comparable results in improvement of the patients' symptoms, although betamethasone phosphate was significantly more effective than clobetasone butyrate in improving the ocular signs of uveitis. In comparing the placebo group of patients with those given topical steroids, the former group, though improving, appeared to lag behind by approximately 1 week. Four patients receiving placebo, however, had to be withdrawn because of worsening of the condition. Mild cases of anterior uveitis would probably resolve without using topical steroids.