Quadricuspid aortic valve is a rare congenital malformation of the aortic valve. Even in the era of a transthoracic and transesophageal ultrasound the occurrence is sometimes missed. Aortic incompetence occurs usually in 5th or 6th decade of life requiring surgical intervention. We report on a 70-year-old woman who presented with exertional dyspnea. In a diagnostic setting transthoracic ultrasound, helical computed tomography scan of the chest and coronary angiography including aortography were performed. Unusual aortic valve anatomy was not described as it was not expected. Finally, the diagnosis of this congenital malformation was established intraoperatively.