Objectives: The aim of this study is to evaluate both clinically and radiographically the efficacy of Platelet-Rich Fibrin as a graft material in osteotome-mediated sinus floor elevation technique with simultaneous implant placement. Materials and methods: Sixteen dental implants were placed simultaneously with osteotome sinus floor elevation in the posterior maxillary area and were divided into groups. Group (A): Eight dental implants were placed simultaneously with osteotome sinus floor elevation using platelet-rich fibrin as a graft material (study group). Group (B): Eight dental implants were placed simultaneously with osteotome sinus floor elevation with no graft material (control group). Clinical evaluation for all cases immediately after surgery, 14 days postoperatively, 6 months after surgery and 9 months after surgery. Radiographic evaluation was performed using standardized digital radiographs (panoramic radiograph) immediately after surgery, 6 months after surgery and 9 months after surgery. Analysis of data was performed using SPSS 17 (Statistical Package for Scientific Studies) for Windows. Results: The control and study groups showed increase in endosinus bone gain at 6 and 9 months postoperatively although more bone is gained when platelet rich fibrin is used. Percent increase in bone height from immediate post-operative to 9 months post-operative in both the mesial and distal sides combined revealed greater mean percent increase in the study group with statistically significant difference. Conclusion: PRF can stabilize high volume of natural regenerated bone in the subsinus area. PRF had a positive effect in osteotome sinus elevation technique. The PRF protocol is finally a way to transform natural blood clot into clinically usable bioactive material.