Purpose: The autogenous bone block graft is regarded as the gold standard material due to reported osteoconductive, osteoinductive, and osteogenic properties. Various intraoral donor sites for autogenous block grafts are presented in the literature. The aim of this study was to radiographically evaluate the maximum dimensions, volume, and bone quality values of these sites. Materials and Methods: According to the inclusion criteria, 50 cone beam computed tomography (CBCT) images from 50 subjects were evaluated. The maximum length, width, height, and volume of autogenous regions where block grafts could be harvested were measured. Radiographic bone quality was calculated by using Hounsfield units derived from CBCT (CBCT-HU). Results: The mean age of 50 subjects (19 men and 31 women) was 55.84 +/- 15.9 years. In this study, the symphysis was the largest potential donor site (3.14 +/- 1.05 cm(3)), while maxillary tuberosity was the smallest (0.53 +/- 0.34 cm(3)). These results correlated with bone density values, where the symphysis retained the highest values (937.31 +/- 160.59 CBCT-HU) and the maxillary tuberosity had the lowest values (360.87 +/- 141.48 CBCT-HU). Conclusion: Intraoral bone blocks have restrictions due to surrounding vital anatomical structures. The surgeons should consider these vital structures using accurate CBCT evaluation. The volume and density of the maximal bone harvest from the symphysis was statistically higher in comparison with ramus, palatal, and maxillary tuberosity bone blocks.