INTRODUCTION
Quadricuspid aortic valve (QAV) is a very rare congenital cardiac abnormally, far less common than unicuspid or bicuspid aortic valve.1 Aortic dilatation and other structural cardiac abnormalities in patients with QAV are relatively common. Aortic valve regurgitation is the main hemodynamic abnormality and the indication for aortic valve surgery in the majority of patients who undergoing surgery.2 Here, a 13-year-old patient with QAV who presented to the outer center with a complaint of chest weight, who was mistakenly diagnosed with insidious rheumatic carditis due to aortic regurgitation, was presented, and and it was aimed to draw attention to this rare congenital heart valve disease.