We have treated 10 patients (five women and five men) with lichen sclerosus (LS), verified by histopathological studies from skin biopsies, with CO2 laser vaporization. All men studied had LS of the penile skin, of the women, three had extragenital lesions and two LS of the perineal skin. The mean follow-up time was 32 months (range 3-79 months). One man had both penile and urethral LS. All penile lesions of the five men were clinically cured by laser treatment: however, urethral lesions of one patient recurred despite three separate treatments. The two women with perineal LS improved after laser treatment. However, LS recurred on the treated are in one and on the margins of the treated area in another. Two women with LS on the skin of the breast became asymptomatic after treatment. One woman had several lesions on the skin of the trunk that improved after treatment but were not cured completely. The present study suggests that carbon dioxide vaporization may be an effective treatment of skin lesions in LS.