The efficacy and tolerability of tazarotene 0.1% gel and tretinoin 0.1% microsponge gel were evaluated in a multicenter, double-blind, randomized, parallel-group study in patients with mild-to-moderate inflammatory facial acne vulgaris. A total of 169 patients were randomized to once-daily applications of one of these topical retinoids for 12 weeks. Both agents were associated with significant reductions from baseline in the noninflammatory and inflammatory lesion counts. Tazarotene treatment was associated with a significantly greater incidence of treatment success (defined as > or = 50% global improvement [67% vs 49%; P=.03]) and significantly greater reductions in overall disease severity (36% vs 26%; P=.02) and noninflammatory lesion count (60% vs 38% at week 12; P=.02) than tretinoin microsponge treatment. Both drugs were well tolerated, with mean levels of dryness, burning, pruritus, erythema, and peeling generally being no more than trace throughout the study. There were no clinically significant between-group differences in these measures of tolerability. Two patients in each group (2%) discontinued because of treatment-related adverse events. The mean amount of medication applied by the patients was 0.28 g per application with tazarotene and 0.41 g per application with tretinoin microsponge, resulting in cost-effectiveness ratios of $81.45 per treatment success with tazarotene and $108.24 per treatment success with tretinoin microsponge. Tazarotene was observed to have greater efficacy and comparable tolerability and to be a cost-effective alternative to tretinoin 0.1% microsponge gel.