Aim: This study aims to evaluate clinically and radiographically the effect of tricalcium phosphate combined with collagen membrane in treatment of intraosseous defects in chronic periodontitis patients. Subjects and methods: Fifteen patients with chronic periodontitis with intraosseous defects has pocket depth > 6 mm and CAL ≥ 5mm after cause related therapy on both sides, with radiographic evidence of vertical bone loss. Following phase I therapy were classified into two groups, group A received defects received open flap debridement alone and group B received open flap surgery augmented with tricalcium phosphate bone graft covered with collagen membrane . Clinical and radiographic parameters were recorded at baseline,3, 6,9 and 12 months postoperatively. Results: Both treatment groups showed a significant probing pocket depth (PPD) reduction, clinical attachment gain, increase bone density 12 months after surgery compared with baseline. However, there was a highly significant PPD reduction and clinical attachment gain when collagen membrane was added to β-TCP. Conclusion: β-TCP plus collagen membrane may lead to improved clinical outcomes compared to open flap debridement alone.