The purpose of this study was to evaluate and compare the effects of Platelet Rich Fibrin (PRF) usage combined with graft and as a membrane on healing of bone defects. For that purpose, four defects were constituted in each parietal bone of 14 Vienna rabbits. First defect was untreated as control (Group A), graft (HA/TCP) and collagen membrane were used in second defect (Group B), HA/TCP and PRF membrane were used in third defect (Group C) and combined HA/TCP – PRF graft and collagen membrane were used in fourth defect (Group D). All samples were sacrificed at post-operative 4th week ( n : 7) and 8th week ( n : 7) periods. Bone defect healing were evaluated histopathologically. It is found that there is a statistically significant difference between four groups in new bone generation for 4 and 8 weekly periods( p : 0.042 vs p : 0.015). At both periods, new bone generation is the highest in Group C, and; Group D, Group B and Group A come after sequentially. As a conclusion, highest new bone formation was determined in group which PRF membrane were used when compared the other groups both at 4th and 8th weeks. It is shown that PRF is a successful autologenous alternative to collagen membrane.