This is the compilation of literature on Etiology, Prognosis, Management, Standard operating Procedures, Current Trends and future Perspectives in Endodontic Retreatment.The post-treatment endodontic disease is defined as "the presence of a periradicular inflammatory lesion (apical or lateral) in an endodontically treated tooth when the lesion can no longer be assumed to be undergoing healing after root canal treatment". At this stage a radiographic examination would reveal inflammation and bone destruction as a radiolucency around the tooth apex.Arriving at a conclusion, whether there is a need for retreatment is the first step followed by deciding the means of retreatment, if required. Conventional endodontic retreatments are different from routine endodontic therapy in that the tooth already has been treated without success, a permanent restoration usually has been placed, and iatrogenic procedural errors must be dealt with. Furthermore, the prognosis for retreatment is much poorer than that for routine conventional endodontics.