| This study was aimed to verify the individual or combining effect of platelet-rich plasma (PRP) and unique biodegradable silicate 45S5 bioactive glass (BG) scaffold on regeneration of metaphyseal tibia defect in a rabbit model. Thirty-six animals were allocated into three groups (n=12 each). In each group, during surgery, right-sided defects were filled with BG, PRP or BG/PRP (1:1), while left-sided defects were served as a control. To visualize and trace defects healing, macroscopic, radiologic and histological examinations were performed at different time points. Bone density/radiopacity and macroscopic (defect size) values were collected and analyzed statistically. Histomorphometric quantitative analysis of H&E stained sections to quantify the percent bone formation at 6 and 8 weeks after implantation was also performed. The gained results showed a significant increase of bone regeneration by 60 days in both BG and BG/PRP-groups (P<0.05 and P<0.001, respectively). Whereas, the healing pattern created by PRP/BG was better comparing to that of BG alone. We noticed unexpectedly incomplete defect closure in PRP-group by 60 days, even though and interestingly, PRP alone accelerated bone radiopacity and new osseous formation significantly only at early stages of healing period (P<0.01). Histomorphometric analyzed data indicated an increasing bone formation over time in all treated defects except PRP during 8 weeks. In conclusion, PRP alone does not provide an appreciated healing effect; however, in future, use of PRP combined with 45S5 BG might be clinically beneficial for proper bone regeneration as safe and appropriate biomaterial.