The primary goal of endodontic surgery is to eliminate periradicular pathology and aid regeneration of the periapical tissues including the complete healing of osseous defects. Apico-marginal defects are localized bony defects that include the entire length of the root i.e., defect which extends from the periapex to the alveolar crest to the tooth. This defect caused by combined periodontal-endodontic lesion or an endodontic-periodontal lesion. The treatment of endodontic-periodontal combined lesions requires both endodontic therapy and periodontal regenerative procedure. Advancement in newer guided tissue regeneration technique and development of second-generation platelet concentrate, platelet rich fibrin shows promising result in field of endodontic surgery. PRF promotes healing of wound, flap stabilization, osseous growth and hemostasis. The present study assess the one-year postoperative healing outcome of Apico-marginal bone defects treated by endodontic microsurgery using two guided regenerative technique. The GTR technique compared included placement of a collagen membrane with and without the adjunctive utilization of PRF over the apico-marginal and osseous defect before flap closure after performing endodontic microsurgery.