Aim: This study seeks to evaluate clinically and radiographically the effects of collagen-chitosan-nanohydroxyapatite membrane in the treatment of periodontal intrabony defects. Materials & methods: Thirty-six patients participated in this study and were divided into three groups, each consisting of 12 cases: Group I received open flap debridement (OFD) only, Group II got OFD with collagen, chitosan, and nanohydroxyapatite membrane, and Group III underwent OFD with collagen type I membrane. Data were obtained at baseline, 3 months, and 6 months regarding plaque index (PI), modified sulcular bleeding index (MS), probing depth (PD), clinical attachment level (CAL), and radiographic measurements were statistically analyzed and compared. Results: There were no significant differences in PI, MS, or CAL at baseline, 3 months, or 6 months among the three groups. There was no significant difference in PD at baseline or 6 months between the three groups. There was no significant change in PD between groups I and II at 3 months. At 3 months, group I's PD decreased significantly as compared to group III's. At 3 months, group II's PD decreased much more than group III's. Conclusion: Despite limitations, this study suggests that collagen-chitosan Nanohydroxyapatite membrane improve the clinical attachment level and pocket depth.