The efficacy of adapalene for acne treatment has been established. However, because of local adverse reactions, a fair number of patients discontinue adapalene treatment before experiencing its effects. To examine the usefulness of moisturizers concomitant with adapalene on adherence to treatment and its therapeutic effects in patients, 100 patients with mild to severe acne vulgaris were randomly assigned to one of two groups: group A, in which patients received adapalene in combination with a moisturizer (heparinoid); or group B, in which treatment consisted of adapalene alone and was converted to combination therapy with a moisturizer if local adverse reactions occurred that made adherence to treatment difficult. After 4 weeks of treatment, we compared the proportion of patients who adhered to therapy until the end of week 4, the number of treatment dropouts, and changes in the number of inflammatory eruptions and comedones between the groups. All of the patients in group A and 70% in group B continued the initial therapy until the end of week 4. In group B, three patients withdrew their consent and one patient stopped attending follow-up visits. The treatment period with the initial therapy was significantly elongated by the concomitant use of a moisturizer. No adverse effect of the use of a moisturizer was observed on the number of comedones and inflammatory eruptions. The concomitant use of a moisturizer with adapalene from the beginning of treatment did not affect its therapeutic effects and helped to improve adherence to treatment with adapalene.