Histiocytosis-X is an uncommon disease, but is relevant to the otolaryngologist because patients with this malady present with, or ultimately develop, head and neck manifestations. Sixty-two patients with histologically confirmed histiocytosis-X have been examined at the Hospital for Sick Children in London since 1958. Most patients were under 2 years of age on initial examination and had either osseous or dermatologic disease involvement. Less commonly, otic or oral lesions were found. Histiocytosis-X is a systemic disease and must be treated accordingly. Isolated lesions may mimic common disease processes, therefore it is imperative that if a seemingly simple problem does not resolve with routine therapy, further patient evaluation be undertaken, If diagnosed, histiocytosis-X can generally be controlled with steroid therapy, or in more recalcitrant cases, by the addition of chemotherapy.