The quadricuspid aortic valve is considered a rare cardiac malformation, as well as an exotic aetiology of aortic regurgitation.The detection of this cardiac anomaly can be done via transthoracic and/or transesophageal echocardiography, thus highlighting the importance of these imaging modalities, as well as its utility in perioperative clinical decision making.We present the case of a 70-year-old patient with severe aortic regurgitation, who was referred to our institution for aortic valve replacement, in whom a quadricuspid aortic valve was documented intraoperatively.Therefore we believe it is valuable to share this case, present intraoperative echocardiographic images, and review the pertinent literature on this subject.