Adapalene, a naphthoic acid derivative with retinoid-like activity, is used for the topical treatment of mild to moderate acne vulgaris. It binds to retinoic acid receptors found predominantly in the terminal differentiation zone of epidermis and is more active than tretinoin in modulating cellular differentiation. Adapalene exhibits anti-inflammatory activity in various in vitro and in vivo models. To date, adapalene 0.1% gel and lotion formulations have been compared only with tretinoin 0.025% gel. In these comparisons, adapalene 0.1% aqueous gel was at least as effective as tretinoin and in some studies was significantly better at reducing the numbers of noninflammatory, inflammatory and total facial lesions in patients with mild to moderate acne. In such comparisons, the cutaneous tolerability of adapalene aqueous gel was generally better than that of tretinoin. On the basis of published data, adapalene aqueous 0.1% gel is an effective and generally better tolerated alternative to tretinoin 0.025% gel for the topical treatment of patients with mild to moderate acne.