Aim To present the endodontic management of a patient diagnosed with a high‐flow arteriovenous malformation (AVM) requiring root canal treatment and to discuss the relevant endodontic literature for this rare but significant problem. Summary AVM is a complex communication of an artery and a vein in which the oxygenated blood is forced away from the intended tissue. The incidence of its occurrence in the face and neck is rare, and when present, the most common sign is gingival bleeding. Arteriovenous malformation is both a diagnostic and therapeutic challenge for dentists. Also, there is ambiguity regarding the precautions to be taken whilst doing endodontic procedures in such cases. Hence, there is a need to understand the disease process and its implications in order to prevent life‐threatening complications during treatment. This case report highlights the successful endodontic management of a cariously exposed right maxillary second premolar in a patient diagnosed with high‐flow AVM. On an orthopantomogram, the AVM was spreading in the left submandibular space involving the left ramus area. The clinical findings of limited mouth opening with inter‐appointment swelling and trismus during treatment made the case unusual and challenging. This paper addresses the current understanding of the classification, diagnosis, clinical features and endodontic management, together with specific guidelines and recommendations whilst performing endodontic procedures in AVM cases. Key learning points The classification and oral manifestations of AVM must be known and understood. Practitioners should be aware of the radiographic appearance of AVM. Recommended precautions should be taken when carrying out restorative and endodontic procedures in a patient with AVM. Antibiotic prophylaxis may be considered before endodontic treatment in a patient with AVM. Multidisciplinary treatment planning may be required.