An azygous anterior cerebral artery is a rare anatomical variant of the Circle of Willis. It is characterised by the absence of the anterior communicating artery and the union of proximal segments to form a single vessel supplying both cerebral hemispheres. Occlusion or stenosis of the single vessel and lack of collateral circulation can lead to bilateral frontal cerebral infarctions, an otherwise relatively uncommon presentation. Knowledge of such an anatomical variant is vital for adequately investigating and managing patients presenting with bilateral anterior cerebral artery territory strokes.