Quadricuspid aortic valve (QAV) is a very rare congenital abnormality. Here, we present a rare case of QAV incidentally noted in a patient at an advanced age during transthoracic echocardiography (TTE). A 73-year-old man with a history of hypertension, hyperlipidemia, diabetes, and treated prostate cancer was admitted to the hospital with palpitations. An electrocardiogram (ECG) showed T-wave inversion in V5-V6, with initial troponin levels mildly elevated. Acute coronary syndrome was ruled out by serial ECGs that were unchanged, and troponins downtrended. TTE showed a rare and incidental finding of type A QAV with four equal cusps with mild aortic regurgitation.