Background Langerhans cell histiocytosis (LCH) is a spectrum of a rare clinico-pathological diseases characterised by the proliferation of histiocyte-like cells that are accompanied by varying numbers of eosinophilic leukocytes, lymphocytes, plasma cells and multinucleate giant cells. It is classified according to its clinico-histological pattern into solitary eosinophilic granuloma or multifocal eosinophilic granuloma (Hand–Scuhller–Christian disease and Letterer–Siwe disease). Aims To report a case of a 44-year-old female who presented with a recurrent swelling of the gingiva in the right mandibular premolar region where non-specific clinical and histological findings initially camouflaged LCH. Results The clinical features and routine histology of this case will be presented as well as the results of S-100 protein and CD1a antigen immunohistochemistry. The diagnostic and treatment methods will also be reviewed and discussed. Conclusion The cumulative evidence of oral involvement with LCH shows the importance of considering LCH as a differential diagnosis for patients showing atypical oral clinical manifestations and/or unexplained radiographic pathology. Infrequently, a case originally diagnosed with chronic focal LCH may progress to multifocal or even disseminated disease, hence clinical work-up subsequent to the diagnosis of a focal oral LCH is important to exclude systemic involvement and prevent further complications.