Objectives: The objective of this study was to evaluate the surface resorptionof autogenous block grafts covered with PRF membrane versus those covered with collagen membranes.Methods:In a randomized clinical trial, 16 patients underwent autogenous block grafts for augmentation of anterior maxillary deficient ridges. In the test group, the block was covered with PRF, whereas in the control group, the block was covered with a collagen membrane. Measurements of clinical and radiographic resorption of autogenous block grafts were carried out at three different time periods (T0, T1, and T2)Results: Results revealed no statistically significant difference in graft resorption between both groups. The test group showed overall graft resorption of 15.27% clinically and 12.07% radiographically compared to 25.53% clinically, and 18.45% radiographically in the control group. Histomorphometric evaluation showed a statistically significant higher value of area percent of vital bone in the test group as shown by the presence of lacunae containing osteocytes in Hematoxylin and Eosin stained sections compared to the control group (Collagen Membrane)Conclusion:PRF membranes can be used to enhance the vitality and integration of autogenous bone blocks in an attempt to reduce the graft resorption in the first four months period. Further randomized controlled clinical trials with larger sample size are needed to confirm the results of this study.