Quadricuspid aortic valve (QAV) is a rare congenital cardiac defect. Aortic regurgitation is the predominant hemodynamically relevant abnormality in patients with QAV, and the main reason for patients requiring valve surgery. Calcific valve disease of the left heart valves is classified as 'low embolic risk' according to current guidelines. However, it remains an important risk factor of cardiovascular events, including ischemic stroke. A 71-year-old woman presented with new-onset aphasia and hemiparesis of the right side of her body. A magnetic resonance imaging scan of the brain showed acute infarction in the supply area of the left middle cerebral artery. Transesophageal echocardiography revealed a QAV with thickening of the leaflet tips and focal calcifications, especially in the coaptation zones. The four cusps were of equal size and symmetrically affected by sclerosis and calcific deposits, and the aortic valve area was 3.2 cm2 with moderate aortic valve regurgitation.