One of the most important skills for dental practitioners to attain is the ability to provide safe and effective local anesthesia. However, failure in local anesthesia in dentistry is not uncommon. In endodontics, achieving adequate anesthesia in cases associated with acute painful pulpitis is considered a major clinical challenge. Successful Inferior Alveolar Nerve Block (IANB) numbs the soft tissues around the tooth to be treated, but it does not always anaesthetize the inflamed pulp Lack of success in obtaining complete anesthesia can be due to patient-related factors or operator-related factors. The patient related factors can be further categorized into anatomical, pathological or psychological factors. Management of local anesthetic failure can be through repeating the primary injection in case of absence of positive signs of success. However, in presence of positive signs of successful primary injection, supplemental injections should be considered. There are several supplemental injection techniques available to help achieving proper anesthetic effect.