After thorough clinical, radiological and histopathological examination, Maxillofacial Surgeon Dr. S. M. Balaji diagnosed it as odontogenic keratocyst (OKC) involving right body and ramus of the mandible. He planned to remove the entire lytic lesion and reconstruction of the affected portion of the mandible in the same surgery. Costochondral graft was harvested from the ribs to reconstruct the mandible. Through intraoral approach, after raising gingivomucoperiosteal flap extending distally, the entire lesion along with the affected portion of mandible was removed in toto. Harvested rib graft was used to reconstruct the defective region of mandible. Patient is very happy to have both removal of lesion and reconstruction of the affected portion of mandible in the same surgery.