Langerhans cell histiocytosis (LCH) in the mandible is a rare disease. LCH was formerly known as histiocytosis X. Histiocytosis X is a granulomatous condition that derives form a clonal proliferation of histiocytes. It has a variable clinical course. LCG may be local or disseminated. It is a reactive disorder or a truly malignant process. This article describes a case of a 45 - year old man with Langerhans cell histiocytosis in his jaw (Fig. 4, Ref. 11).