Local anesthesia is indispensable in dentistry. Worldwide, millions of local anesthetic injections are administered annually, and are generally considered safe invasive procedures. However, adverse effects are possible, of which dentists should be aware of. This scoping review aimed to provide an extensive overview of the reported literature on the adverse effects of dental local anesthesia. The types of papers, what is reported, and how they are reported were reviewed. Additionally, the incidence and duration of adverse effects and factors influencing their occurrence were also reviewed. An electronic search for relevant articles was performed in PubMed and Embase databases from inception to January 2, 2020. The titles and abstracts were independently screened by two reviewers. The analysis was narrative, and no meta-analysis was performed. This study included 78 articles. Ocular and neurological adverse effects, allergies, hematomas, needle breakage, tissue necrosis, blanching, jaw ankylosis, osteomyelitis, and isolated atrial fibrillation have been described. Multiple adverse effects of dental local anesthesia have been reported in the literature. The results were heterogeneous, and detailed descriptions of the related procedures were lacking. Vital information concerning adverse effects, such as the dosage or type of anesthetic solution, or the type of needle used, was frequently missing. Therefore, high-quality research on this topic is needed. Finally, the adverse effects that are rarely encountered in real-world general practice are overrepresented in the literature.