Langerhans cell histiocytosis (LCH), is a rare, proliferative disorder in which the accumulation of pathologic Langerhans cells leads to local tissue infiltration and destruction. We present a case of a 32 years old, completely edentulous female patient who presented with erythema of hard palate, maxillary alveolar mucosa and mucosa over the distobuccal part of mandibular alveolar ridge with foci of ulcerations. Histopathologic features were suggestive of LCH which was confirmed by immunohistochemistry which was CD1a positive, confirmatory for LCH. Bone scan revealed multiple bone involvement. At this stage, disease had already progressed to multisystem involvement with endocrinal abnormalities (primary hypothyroidism and hyperprolactinemia), requiring aggressive treatment. Therefore, this case is a reminder of the possibility of occurrence of this rare disease in the oral cavity which might manifest itself in multiple presentations thus easily leading to the misdiagnosis and therefore, it could be easily overlooked by dentists.