This study aimed to evaluate the efficacy of platelet rich plasma (PRP) and advanced platelet rich fibrin (A-PRF) on regeneration of induced tibial bone defects in dogs. A 7mm circular and 10mm deep tibial defect was made at upper end of the right and left tibiae of 12 adult clinically-proven healthy male mongrel dogs. The animals were randomly divided into three groups: a control group, PRP group and A-PRF group. Regeneration of the tibial defect was evaluated by radiography, computed tomography (CT), and histopathological examination at 6 and 12 weeks postoperatively (PO). At 6 weeks PO, the tibial defect, in the control group, was partially filled with fibrous tissue and appeared radiolucent under radiography. While in PRP group, the defect was shown to be partially filled with newly formed bone and appeared more radiopaque than it did with the control group. As for APRF tibial defect, it was completely closed with newly formed bone and appeared more radiopaque than the PRP group did. At 12 weeks PO, the tibial defect was partially filled with newly formed bone and looked more radiopaque in control group and completely closed with newly formed bone and seemed radiopaque in PRP group. Interestingly, the tibial defect of the A-PRF group was completely closed with newly formed bone and couldn’t have been differentiated from the neighboring normal bone tissue. In conclusion, using of PRP and A-PRF improved bone healing. However, using A-PRF is more likely to heal tibial defect in the early weeks of injury than PRP would.