We describe an unusual case of keratotic lichen sclerosus with extragenital and genital lesions in a 34-year-old Brazilian man. The disease was characterized by several erythematous and brownish keratotic papules on the man's back, trunk and extensor areas of the limbs; histologic findings were typical of lichen sclerosus. Others atypical extragenital forms of lichen sderosus are discussed.