Local anaesthetics are an integral part of most dental procedures and are therefore widely used and safely applied. Though rare, complications may occur and can be categorized as local or systemic. In the majority they are of minor nature but there is a potential for severe and possibly lethal side effects. Local complications are nerve damage (mainly the lingual and the inferior alveolar nerve), lesions of vascular structures, hematoma formation, temporary palsy of the facial nerve and post injection pain being the most common local complication. Examples for systemic complications are allergic reactions, cardiovascular complications, intoxication and psychogenic reactions.