Endodontic-periodontal combined lesion is a clinical dilemma because, arriving at a differential diagnosis and deciding a prognosis is difficult. An untreated primary endodontic lesion can become secondarily involved with periodontal breakdown, which may clinically present with unusual signs and symptoms. This can delay the diagnosis and formulating the correct treatment. This case report describes the diagnosis and treatment protocol for an Endo-perio lesion of primary endodontic with secondary periodontal involvement.