This study was conducted to evaluate bone defects healing in the medium or large size maxillary bone cysts using beta Tri-calcium phosphate with addition of platelets rich plasma. Twelve patients aged between 20-35 years, suffering from maxillary bone cysts of average size were divided randomly into two equal groups. Study group was treated using a combination of beta Tri-calcium phosphate with platelets-rich plasma and patient whole blood, while Control group treated using the beta Tri-calcium phosphate mixed with patient whole blood only. All teeth related to the bone cysts were endodontically treated before the procedure. All cases were evaluated clinically and radiographically before surgery, immediately after, three months and six months after surgery using digital orthopantomography. Bone density was measured by DIGORA software. Results were collected, tabulated and analyzed statistically using (student T test). Results: Clinical evaluation of the two groups did not show any evidence of bone graft rejection. There was significant decrease in digital bone density measurements after three months compared to immediate postoperative density, while after sixth months there was significant increase in bone density compared to three months density but still less than immediate postoperative density in both groups. There was no significant difference in digital bone density and adverse effects between groups throughout the study periods. Conclusion: Combination of beta Tri-calcium phosphate with platelets-rich plasma has no advantage on bone density compared to beta Tri-calcium phosphate alone in treatment of maxillary bone cysts.