Eosinophilic granuloma is a disease of the reticuloendothelial system and its pathogenesis is not yet completely clear. The histopathological findings are granulomatous proliferation of histiocytes accompanied by diffuse infiltration of eosinophils.We recently experienced a case of eosinophilic granuloma arising monostotically in the body of the mandible in the 76 region. There has been no local recurrence 17 months after surgical removal of the lesion.