Topical retinoids are often recommended for preventing acne recurrence, but there are relatively few well-controlled maintenance studies published. The objective of the present study was to assess the maintenance effect of adapalene gel 0.1% relative to gel vehicle in subjects successfully treated in a previous 12-week adapalene-lymecycline 300 mg combination therapy study. This was a multicentre, investigator-blind, randomised, controlled study in 19 European centres. A total of 136 subjects with moderate to moderately-severe acne vulgaris who showed at least moderate improvement from baseline when treated with either adapalene plus lymecycline or lymecycline plus gel vehicle in a previous 12 week study were included. Subjects were randomised to receive adapalene gel 0.1% or vehicle once-daily for 12 weeks. Efficacy and safety criteria included maintenance rate, percent reduction in lesion counts (total, inflammatory, non inflammatory), global severity assessment, cutaneous tolerability, and adverse events. Adapalene provided better results relative to gel vehicle for all efficacy assessments. The maintenance rate for total lesions was 84.7% vs. 63.5% (P = 0.0049) with adapalene and the vehicle, respectively. Adapalene was safe and well tolerated in this study. This study demonstrates a clinical benefit of continued treatment with adapalene gel 0.1% as a maintenance therapy for acne.