Abstract This multicenter, randomized, investigator-blinded study compared the efficacy and tolerability of a combination of lymecycline 300 mg/day orally and adapalene topical gel 0.1% (n = 118) to lymecycline 300 mg/day orally plus vehicle gel (n = 124) in patients with moderate to moderately severe acne vulgaris with both inflammatory and noninflammatory lesions. The primary efficacy end point, total lesion count at end point (last observation carried forward), showed a statistically significant difference in favor of the lymecycline plus adapalene group ( P = .0011). The mean decrease in total, inflammatory and noninflammatory lesion counts was significantly greater at end point in the lymecycline plus adapalene group than in the lymecycline plus vehicle group ( P < .01). In addition, a significant difference for inflammatory and total acne lesions was seen sooner in the adapalene plus lymecycline group. In total, 75.5% of patients in the lymecycline plus adapalene group were markedly improved, almost clear or clear of their lesions at week 12, compared with 51.8% of those in the lymecycline plus vehicle group ( P < .001). Local cutaneous tolerance was generally good in both groups, although more patients receiving the lymecycline plus adapalene combination experienced cutaneous reactions than those receiving lymecycline plus vehicle. There are relatively few studies comparing the efficacy of combined oral and topical therapy with either individual therapy alone. This study clearly demonstrates that lymecycline plus adapalene combination treatment resulted in a significantly greater mean decrease in the number of inflammatory, noninflammatory and total lesions than lymecycline plus vehicle and was well tolerated.