Lichen sclerosus is a chronic inflammatory dermatosis presenting with significant sclerosis, atrophy and pruritus. The treatment for this condition remains unsatisfactory, with potent corticosteroids being the most effective therapy. In this study, we investigated the efficacy and safety of tacrolimus ointment in patients with genital and extragenital lichen sclerosus. Sixteen patients with active lichen sclerosus (10 with anogenital and six with extragenital localization) were treated with topical tacrolimus ointment twice daily. The therapeutic effects were evaluated according to 3 grades: complete response (>75% improvement), partial response (25–75% improvement), or no response (<25% improvement). Applications were continued until complete disappearance or stabilization of the cutaneous lesions. In addition, we conducted telephone surveys to determine the long-term treatment outcome and relapse rate. Objective response to therapy occurred in nine of 10 patients (90%) with anogenital and one of six patients (16.7%) with extragenital lesions. Out of 10 patients with anogenital lichen sclerosus, five showed more than 75% improvement. Complete, partial and no response were achieved in five (50%), four (40%) and one (10%) patient, respectively. During the follow-up period of a mean of 29.3 months, six of nine patients had a relapse of symptoms. However, most patients with extragenital involvement did not respond to tacrolimus, except one patient showing partial response. No significant adverse effects were observed. Topical tacrolimus ointment was a safe and effective treatment for genital lichen sclerosus and should be used for long-term duration to prevent relapse. However, it was not useful for patients with extragenital lichen sclerosus.