Merkersson-Rosenthal syndrome (MRS) is characterized by cheilitis or pareitis granulomatosa, facial palsy, and fissured tongue. Sometimes the forehead, eyelids and chin are involved, and occasionally genital lesions are present. A vulval lesion of MRS is named vulvitis granulomatosa. Tranilast has been described as an effective treatment for cases of MRS, granulomatous cheilitis, and granulomatous blepharitis. Herein we report a successful treatment with tranilast of an adult female patient with vulvitis granulomatosa.