Objective: Assess efficacy and safety of once-daily topical dapsone gel, 7.5% compared with vehicle for treating acne vulgaris (acne). Design: A pooled analysis of data from two identically designed, randomized, double-blind, vehicle-controlled, multicenter, 12-week clinical trials. Setting: Study sites in the United States and Canada. Participants: overall, 4,340 patients were randomized 1:1 to dapsone and vehicle. Criteria included age 12 years or older with acne diagnosis, 20 to 50 facial inflammatory lesions (papules and pustules), 30 to 100 facial noninflammatory lesions (open and closed comedones), and acne grade of 3 (moderate) on the Global Acne Assessment Score scale. Measurements: Efficacy assessments included the Global Acne Assessment Score success rate (proportion of patients with Global Acne Assessment Score of 0 [none] or 1 [minimal]) and percentage change from baseline in inflammatory and noninflammatory lesions at Week 12. Results: Global Acne Assessment Score success rates were 29.8 percent and 21.1 percent for patients who received dapsone gel, 7.5% and vehicle, respectively (p<0.001). Patients receiving dapsone gel, 7.5% had greater percentage change in lesion counts than patients receiving vehicle (inflammatory lesions: -54.6% vs. -48.1%; p<0.001; -45.1 %; noninflammatory lesions: -39.4%; p<0.001). Most adverse events were mild to moderate in severity. Mean dermal tolerability scores for stinging/burning, dryness, scaling, and erythema were similarly low with dapsone gel, 7.5% and vehicle. Conclusion: Dapsone gel, 7.5%, with a 50-percent greater dapsone concentration than twice-daily dapsone gel, 5% formulation, is applied topically once daily for acne, is effective, safe, and well-tolerated over 12 weeks, and has local tolerability similar to that of vehicle. www.clinicaltrials.gov identifiers: NCT01974141 and NCT01974323.