Intentional replantation is defined as extraction of the tooth followed by replacement in its socket. Intentional replantation is considered as a last resort where surgical endodontics or conventional root canal therapy cannot be performed. Factors determining success in intentional replantation are periodontal cell viability, removal of irritant, good apical seal and procedure carried out under aseptic condition with a traumatic extraction. In this article, a case of intentional reimplantation is described and discussed as a treatment approach for failed root canal treatment with separated instrument periapically beyond the apical terminus in mandibular second molar.