Eosinophilic granuloma (EG) is the localized and mildest form of the triad commonly known as Langerhans cell histiocytosis. This report describes a case manifesting itself as a periodontal problem with the localized osseous lesions in jawbones which was first diagnosed as early-onset periodontitis. Later on, the diagnosis of EG was established, relying on histopathological and immunohistochemical evaluations. Immunohistochemical findings confirm that a minor component of cell aggregates is phenotypically related to Langerhans cells among the sheet-like accumulations of histiocytes and eosinophils. The aetiology of the disease remains largely unknown. Although surgical curettage of lesions is usually effective in treatment of EG of bone, corticosteroids might be used as an adjunctive. This multifocal case of EG stresses the importance of clinical follow-up examinations, since the sequential lesions appear with irregular intervals, and this may cause diagnostic problems as well as a delay in starting the treatment regimen.