The effect of autogenous bone marrow injection on healing of mandibular fracture treated by closed reduction and maxillomandibular fixation was evaluated clinically. for fractures suitable20 patients with mandibular. Patients and method: treatment with closed reduction and maxillomandibular fixation were divided into two equal groups. Group (A) control group were treated by maxillomandibular fixation only Group (B) study group were treated by maxillomandibular fixation then fracture line was injected by autogenous bone marrow taken from illiac crest of the same patient. Digital panoramic x-ray views were taken at 0,2,4,6 weeks postoperatively; bone density was evaluated by radiodenstometric study computer program. the bone density in study group was increased in higher rate than. Results: the control group which indicated more bone stability and better and faster bone healing with shorter maxillomandibular fixation period. bone marrow injection in fracture lines is accepted as a. Conclusions: method for acceleration of fracture healing and minimizing treatment period.