Primary Langerhans cell histiocytosis (LCH) of the female genital tract is very uncommon. Since the natural history of this tumor is unpredictable, with spontaneous remissions and exacerbations, establishment of the diagnosis is often difficult. In the few reported cases of LCH involving the vulva there were systemic manifestations of the disease. We report the clinical and histopathological findings in the case of a 36-year-old woman who presented with a 9-year history of vulvar lesions. The diagnosis of LCH was established by immunohistochemical techniques, which demonstrated sheets of S-100 protein-positive histiocytes in the dermal tumor. The patient received radiotherapy to the vulva and responded with complete remission.