This study evaluated the effect of mandibular bone grafts for reconstruction of alveolar clefts. The study included 25 patients with cleft lip and alveolar process only and three patients with unilateral cleft lip and palate, with a median postoperative follow-up of 8 months (range, 6 to 17 months). The bone grafts were obtained from below the mandibular incisors and canines through an intraoral approach. The marginal bone level achieved was satisfactory in all cases evaluated by occlusal radiographs; the radiographs also demonstrated that the bone grafts were totally integrated after 6 months in all cases. The morphology of the reconstructed alveolar process was satisfactory in all cases evaluated and no periodontal complications were seen. The donor site appeared healed radiologically in all cases 6 months after surgery. The advantages gained by using a mandibular bone graft as compared to an iliac crest graft include reduced morbidity, reduced hospitalization time, reduced operating time, and avoidance of scarring at the donor site. The results of the present study demonstrate that the mandibular symphysis can be used as donor site for reconstruction of small alveolar clefts.