INTRODUCTION: Platelet rich fibrin (PRF) is an autologous healing biomaterial composed of a fibrin clot matrix entrapping leukocytes, cytokines, living progenitor cells, and platelets capable of releasing various growth factors harvested from a simple blood sample. OBJECTIVES: The aim of this experimental study was to evaluate the effect of PRF on angiogenesis during the periodontal regeneration of surgically created grade ΙΙ furcation defects in dogs. MATERIALS AND METHODS: A split mouth design was carried out using the third and fourth mandibular premolars of 2 healthy mongrel adult dogs. A total of eight grade II furcation defects were surgically created. The defects in the study side were augmented with PRF mixed with a β-TCP and covered by a PRF membrane and a collagen membrane. In the control side the defects were augmented with β-TCP and covered with a collagen membrane. The dogs were sacrificed after 1 and 2 months. Samples were dissected and prepared for histological evaluation. RESULTS: Histological results showed that PRF addition led to higher vascularization of the study samples at all age groups; this was evident at one month in the form of numerous blood vessels entrapping RBCs and at 2 months by the presence of red bone marrow and blood vessels entrapping RBCs within. CONCLUSIONS: The addition of PRF to β -TCP was found to be effective in enhancing angiogenesis during the periodontal regeneration of grade II furcation defects