The treatment of vulvar lichen sclerosus is generally considered difficult. Ultrapotent corticosteroids represent the most effective topical treatment, but carry the risk of side effects such as skin atrophy. We describe a 71-year-old woman with long-standing vulvar lichen sclerosus refractory to conventional treatment. After 6 consecutive weeks of treatment with tacrolimus ointment 0.1% (Protopic) twice daily, signs and symptoms of lichen sclerosus resolved. To our knowledge, this is the first report of the use of topical tacrolimus, which does not induce skin atrophy, in the treatment of vulvar lichen sclerosus.