BACKGROUND AND OBJECTIVES Zinc plays a role in skin health, and preliminary data have shown its beneficial effects for melasma. We compared the effect of topical zinc with that of hydroquinone as the standard treatment on severity of melasma. PATIENTS AND METHODS Ninety-three women with melasma were randomized to receive zinc sulfate 10% or hydroquinone 4% solutions once daily for 2 months. They were followed for an additional 3 months while using sunscreen. The severity of melasma was assessed at baseline and at 2 and 5 months using the Melasma Area and Severity Index (MASI). RESULTS Eighty-two patients completed the study. The MASI score fell significantly in both groups, but a greater decrease was seen in those who received hydroquinone (43.5 ± 15.5% vs 18.6 ± 20.8%, p < .001). Postinflammatory pigmentation occurred in 5.2% of the zinc group and irritation in 30.9% of the hydroquinone group. CONCLUSION Topical zinc therapy is not highly effective in reducing the severity of melasma, but further trials are needed to determine whether adding zinc to current topical treatments could improve treatment response.