Background: The efficacy and safety of daily maintenance treatment with an adapalene-benzoyl peroxide (adapalene-BPO) fixed-dose combination gel is established in acne vulgaris in adults. Objective: This study evaluated the efficacy and tolerability of twice-per-week maintenance therapy with an adapalene-BPO combination gel for acne vulgaris in adults. Methods: All patients applied the adapalene-BPO combination gel once daily during the initial 8 weeks. Subsequently, the patients were randomized into two groups. The maintenance group applied the ointment twice- per-week for 12 weeks of maintenance treatment, while the control group discontinued treatment after the initial 8 weeks active treatment. The changes in the mean numbers of total, inflammatory, and non-inflammatory lesions were assessed. Results: During maintenance treatment, the changes in the average numbers of total and inflammatory lesions in the maintenance group differed significantly from the control group. Conclusion: Twice-per-week application of an adapalene-BPO combination gel after active treatment appears to be a good option for the maintenance therapy of acne vulgaris in adults. (Korean J Dermatol 2016;54(2):119∼124)