The purpose of this study is to evaluate the effects of OSTEON, PRP and the combination of both of them on the healing of experimentally induced bone defects in rabbits. Materials and Meth-ods: Fifteen domestic rabbits were used in this study; four bone defects were made in the tibia of each rabbit. The defects were filled with OSTEON, PRP, OSTEON / PRP and the other left unfilled as con-trol. Specimens were collected at one, two and four weeks after surgery. Radiographical and histologi-cal examinations were used to evaluate healing depending of the amount of new bone formed. Results: It was found that the OSTEON / PRP combination led to a significant healing compared to other groups at first week only. On the other hand PRP alone showed better result than OSTEON alone in the three periods. Conclusion: It was concluded that PRP plasma exert a beneficial effect on healing pro-cess when added to bone substitute material OSTEON.