BACKGROUND: Topical retinoids are highly effective treatments for acne vulgaris. The various formulations and concentrations available allow physicians to tailor therapies to individual patient's needs and minimize the cutaneous irritation that is often observed with the use of these drugs. OBJECTIVE: To compare the efficacy and safety of tretinoin gel microsphere 0.1% with adapalene gel 0.1% in the treatment of acne vulgaris. Methods: A 12-week double-blind study was conducted, and patients were evaluated at baseline and at weeks 2, 3, 4, 6, 8, 10, and 12. RESULTS: Although the two drugs displayed similar efficacy in the resolution of acne lesions at 12 weeks, a significantly greater reduction in the number of comedones was seen at week 4 among patients treated with tretinoin gel microsphere (p = 0.047). Patients receiving tretinoin gel microsphere had an increased incidence of dryness (weeks 8 and 10) and peeling (weeks 3, 6, 8, and 10) compared with those patients treated with adapalene gel, but the two groups were comparable with respect to erythema, burning/stinging, and itching. CONCLUSION: Both drugs have similar efficacy in the resolution of acne lesions but tretinoin gel microsphere may result in a faster onset of action in the reduction of comedones compared to adapalene.