Although the management of medical relation osteonecrosis of the jaw is usually provided by colleagues in maxillofacial surgery, it is essential for ENT surgeons to effectively diagnose the various presentations of this condition. Affected bone that is exposed and necrotic may remain asymptomatic for prolonged periods with symptoms only developing when surrounding tissues are affected. This can include pain, tooth mobility, ulcers, mucosal swelling and erythema. One important presentation for ENT surgeons to recognise is that of chronic maxillary sinusitis with or without an oro-antral fistula when the disease involves the sinus floor. A high index of suspicion is required in any patients taking antiresorptive therapy, such as oestrogens or bisphosphonates, and in those with malignancies that may metastasise to bone. As well as a thorough history, imaging options include CT, MRI or bone scanning and a histopathologic diagnosis is also useful. The staging classification used by the American Academy of Oral and Maxillofacial Surgery spans from ‘at risk’ to stage 0, 1, 2 and 3 with stage 3 being disease with extraoral fistula or involving the sinus floor. This is a helpful review with a broad coverage of the diagnostic tools for this complex and important condition.