Introduction: The goal of periodontal therapy is to establish a healthy periodontium and restore lost form and function of the supporting alveolar bone, cementum, and periodontal ligament. Furcation defects represent a formidable problem in the treatment of periodontal disease, principally related to the complex and irregular anatomy of furcations. Nano crystalline hydroxyapatite had been introduced for augmentation procedures in osseous defects. Platelet-rich fibrin (PRF) is a second generation platelet concentrate widely used to accelerate soft and hard tissue healing. PRF is a strictly autologous fibrin matrix containing a large quantity of platelet and leukocyte cytokines.Aim of the study: The aim of the present study was to evaluate the use of platelet rich fibrin and Nano-hydroxyapetite as a regenerative treatment in furcation class II defect.Material and methods: Eight young adult dogs, with intact maxillary and mandibular teeth with good systemic and periodontal health will be selected for the study, In each dog 4 premolars will be included in the study (2 in each side) apart from each other and will be treated as follow:First: will be treated withNano hydroxyapatite aloneSecond: will be treated withPRF aloneThird: will be treated withNano hydroxyapatite and PRFFourth: will not receive any additional treatment than debridement (controls).Results: In the present study, through histomorphometric analysis, the greatest value of area percent of newly formed bone was observed in the (PRF+ NHA bone) group, followed by the PRF group, then the NHA group, with the least value recorded in the control group. The difference was none statistically significant except in comparing (PRF+ NHA group) with control group (p<0.05).Conclusions: The combined use of both PRF and Nano hydroxyapatite in treatment of periodontal furcation class II defects could accelerate healing processes getting use of the synergic effect of the powerful inherent regenerative potential of PRF and Nano hydroxyapatite.