The accidental use of drugs is an unacceptable mistake in medicine, but the misuse of different agents has been reported frequently in the literature. While performing local anesthesia before starting dental treatment, the injection of a wrong agent, as a result of confusing the liquid in the syringe may cause local and systemic complications. Sudden swelling, intense pain, and severe allergic reactions may develop in the patient.

A complication causing soft tissue necrosis is presented in this case report in which Ethylenediaminetetraacetic acid (EDTA) was accidentally injected instead of an anesthetic solution. This case report is unique because it is the first to report an inadvertent injection of EDTA in dentistry.