Langerhans cell histiocytosis is a clonal neoplastic proliferation of bone marrow-derived histiocytes (Langerhans-type cells) characterized by unifocal, multifocal single-system, or multisystem disease that occurs in all age groups, but with most cases occurring during childhood. The clinical course of Langerhans cell histiocytosis is considered highly variable and unpredictable, being classified as single-system or multisystem forms. The skin, pituitary and bone, especially the skull, femur, vertebra, pelvic bones, ribs and the jaws, are the most affected locations. The oral and maxillofacial region is involved in about 20%–30% of the cases, and the posterior region of the mandible and the surrounding gingival tissue are the most affected sites. The gingival lesions are painful and ulcerated, often associated with extensive alveolar bone resorption. Microscopically, the disease is characterized by a diffuse proliferation of Langerhans cell histiocytosis cells that typically show grooved, folded, indented or lobed nuclei, and eosinophils are prominent in most cases. The expression of CD1a and CD207 proteins by tumor cells is a hallmark of this disorder. Treatment depends on the extent of the disease, and for single-system presentation, bone curettage, oral indomethacin and/or intra-lesional injections of corticosteroids are recommended, whereas multisystem diseases usually demand systemic chemotherapy.