Local anesthesia is a mainstay in the pain management arsenal in dental offices. Like all other medications, local anesthesia can also result in serious complications, whether they be due to drug toxicity, nerve and vascular injury, unintended nerve involvement or any attendant medical emergency, which may include syncope, psychogenic reactions or myocardial challenge, among others. This clinically relevant presentation will examine all possible complications associated with the use of local anesthetics, including inability to anesthetize.