This study was conducted for evaluation of the efficacy of osteoplant flex sheets (Xenogenic bone substitute) in sinus lifting procedures. A total of 8 patients were included in this study. All patients were subjected to unilateral maxillary sinus lifting procedure through lateral maxillary wall approach. Osteoplant Cancellous Sheet was the grafting material applied in all cases. Osteoplant Cancellous Sheets were used as a tinting mean to elevate and retain the elevated sinus lining (Schneiderian) membrane and also as a bone filling grafting material. All patients were subjected to preoperative clinical and radiographic examination using cone beam computerized tomography (CBCT) scans. Patient follow up postoperatively was performed at 1week, 1 month, and finally 6 months postoperatively when all patients were subjected to CBCT scan. CBCT scan generated bone height and bone density measurements were collected, tabulated, and subjected to statistical analysis. All patients survived well the procedures. Analysis of bone height revealed significantly different increase in bone height postoperatively in comparison to preoperative bone height measurements. Analysis of bone density measurements revealed non-significant decrease in bone density of the newly formed bony regenerate postoperatively in comparison to the old native bone. Our results suggest that the equine enzymatically deantigenated flexible xenograft is considered an efficient bone substitute for maxillary sinus lifting and augmentation procedures.