Background and objectives. In recent years, chemical peels have become increasingly popular in the treatment of melasma. However, postpeel hyperpigmentation is a frequently encountered side effect, especially in dark-skinned individuals. The role of priming agents in preventing this complication has not been adequately evaluated. Hence, we studied the effect of hydroquinone versus tretinoin as priming agents in minimizing the incidence of this side effect in a double-blind, randomized clinical trial of 50 patients with melasma. Methods. Of a total of 50 patients, 25 patients each with a similar skin phototype, the nature and severity of melasma were assigned to groups I and II. The patients were primed with 2% hydroquinone in group I, and in group II with 0.025% tretinoin once daily (night time) 2 weeks before starting trichloroacetic acid peels. Subsequently, all of them received trichloroacetic acid peels at intervals of 2 weeks for 12 weeks, followed by monthly peels for next 12 weeks during the follow-up period. Patients continued to use a sunscreen with an SPF of greater than 15 and the recommended priming agent during the follow-up. Final assessment was made at 6 months, based on the impression of the patient, clinical examination by the physician, and photographic analysis. Results. A total of 50 patients (25 in each group) participated in the study. The predominant Fitzpatrick skin type observed among them was type IV (56%), and the type of melasma was mixed (44%). The final results at 12 weeks were comparable in two groups. However, a significant difference was seen in the two groups during the follow-up period, with continued improvement in 24% and worsening in 28% of patients in group I and continued improvement in only 16% and worsening in 40% in group II patients. Conclusions. Hydroquinone is superior to tretinoin as a priming agent in maintaining the results achieved with peels and in decreasing the incidence of postpeel reactive hyperpigmentation. S. NANDA, C. GROVER, AND B. S. N. REDDY HAVE INDICATED NO SIGNIFICANT INTEREST WITH COMMERCIAL SUPPORTERS.