- Desmoplastic fibroma (DF) is a benign, locally aggressive, bone tumor that rarely presents in the facial bones. It is considered an intraosseous counterpart of the soft tissue fibromatoses. It is very rare in children. The present report describes the clinico-pathological and radiographic features of a desmoplastic fibroma of the mandible in a 12-year-old female who presented with a few months history of an expanding, painless mass along the left inferior border of the mandible. The patient underwent a resection with wide margins of the inferior border of the mandible that was followed by a pathological fracture. The fracture was reduced and the mandible was reconstructed by a vascularized free fibula flap. Conservative surgical approach and long term follow up is an effective treatment modality for mandibular DF in children.