Langerhans cell histiocytosis is a rare idiopathic disorder with protean clinical presentations. Primary unifocal single-system disease of the vulva is even less common. We report a 62-year-old female patient presenting with an 18-month history of pruritus and burning of the vulva. Clinical examination of the vulva showed a tender nodule of the right labium minus. Histology confirmed Langerhans cell histiocytosis. Systemic involvement was excluded. Within 1 month the use of clobetasol propionate ointment led to resolution of both the patient's symptoms and the clinical appearance of the affected right labium minus. This resolution was maintained 12 months later.