Objective : The objective of this study was to determine which forms of iliac cancellous bone grafts better restore alveolar clefts. Study design : Forty consecutive patients who required a unilateral alveolar cleft graft were studied. Group I (20 patients) had reconstruction with iliac cancellous particulate bone grafts and group II (20 patients) had reconstruction with iliac cancellous block bone grafts. The two groups were evaluated radiographically and clinically. Results : The group with the block bone grafts showed less postoperative problems and better incorporation of the bone graft than the group with the particulate grafts. Conclusion : Surgical reconstruction of alveolar process defects in patients with alveolar cleft using iliac cancellous block bone is a more reliable method than particulate bone grafts both for closing the oronasal fistula and for building interalveolar septal height.