Arteriovenous malformation (AVM) of the mandible is a rare and potentially life-threatening condition which can lead to massive hemorrhage. The following is a description where a large mandibular AVM presented along with the congenital cardiac disease. An orthopantomogram (OPG) was performed which was suggestive of hemangioma. A computed tomography (CT) angiography revealed a large mandibular AV malformation. It is important for both clinicians and radiologist to be aware of this type of lesion that can have life-threatening complications. It is important to define the anatomical location and the feeder vessels of the entity in detail preoperatively. This communication highlights the common differential and use of multi-detector CT angiography along with other imaging modalities to prevent a fatal hemorrhage and arrive at a correct diagnosis.