Maxillofacial bone defects occur for various reasons as infections, tumor and cysts or physiologic loss of bone after extraction of teeth. There are a lot of controversies among dental practitioners in the material used for filling of bone defects to increase the volume of bone in favor of good placement of the implant. Autogenous bone is the gold standard for bone reconstruction due to osteogenic, osteoinductive, and osteoconductive properties.The aim of this study was preoperative CBCT assessment of maxillary tuberosity as donor site for purpose of autogenous block graft.20 participants were included in the study, Participants were recruited according to certain eligibility criteria. Radiographic examination was done at Oral and Maxillofacial Radiology Department, Faculty of Dentistry, Cairo University.Linear and volumetric measurements of maxillary tuberosity using segmentation (manual and semiautomatic) were done. Results showed the difference between real and segmented volumes to be statistically significant with real volume being significantly higher than manual and semi-automatic segmentation (p<0.001)and there was a moderate agreement between semi-automatic and manual segmentation that was statistically significant (ICC=0.693, p<0.001) and there was a strong agreement between both observations that was statistically significant (ICC>0.9, p<0.001). CBCT is a valuable tool to assess the linear and volumetric measurements of the block grafts for maxillary tuberosity as intraoral donor site.Maxillary tuberosity tuberosity could be a useful source of autogenous bone graft for the treatment of small and limited defects of the alveolar process.