Objectives: This study aimed at radiographic and histological assessment of the neo-bone formation following maxillary sinus elevation using absorbable gelatin sponge. Materials and Methods: Seven female- patients indicated for maxillary sinus floor augmentation to enable future dental implant placement were participated in this study. Their ages ranged from 23 to 45 years with an average of 37 years. intervals. Fusion of the CBCT images was performed for standardization. Results: The clinical findings include 3 sinus membrane perforations (33%) and 1 postoperative infection (11%). The radiographic results revealed that the bone heights were significantly increased 6 months postoperatively. Bone formation was also verified by histological examination and histomorphometric analysis.