The effects of oral zinc sulfate (corresponding to 135 mg of zinc daily) alone and in combination with vitamin A (300,000 international units) daily on acne lesions have been compared with those of vitamin A alone and of a placebo. The number of comedones, papules, pustules, and infiltrates were counted at each visit. After four weeks, there was a significant decrease in the number of papules, pustules, and infiltrates in the zinc-treated groups. The effect of zinc plus vitamin A was not better than zinc alone. After 12 weeks of treatment, the mean acne score had decreased from 100% to 15%. The mechanism for the effect of zinc therapy in acne, to our knowledge, is not presently known.¿