Localized Langerhans cell histiocytosis (LLCH), formerly known as eosinophilic granuloma, mainly affects the skull, mandible, vertebrae, and ribs in children and the long bones of adults. Symptoms range from none to pain, swelling, and tenderness over the site of the lesion. General malaise and fever occasionally are present. Radiographically, lesions appear as radiolucent areas with well demarcated borders. LLCH may resolve spontaneously after biopsy in a period of months to years. However, if features include continuous pain, decrease of function, pathologic fractures, migration and resorption of teeth, or rapid progression, then active treatment needs to be considered. Treatment approaches include surgery, radiotherapy, chemotherapy, and intralesional injection of corticosteroids. In children with mandibular LLCH, 1 dose of methyprednisolone succinate injection has proven to be adequate. However, injections have not been performed in cases involving pathologic fracture. We report a new case of LLCH of the mandible that caused a pathologic fracture in an adult patient. Repeated intralesional corticosteroid injections resulted in fracture line disappearance within 14 months and lesion healing by the end of the 36-month follow-up.