Quaricuspid aortic valve (QAV) is a very rare congenital heart defect characterized by the presence of four valves of the same or different sizes. This anomaly may cause progressive aortic regurgitation or rarely valve stenosis. The diagnosis of QAV may be difficult, misdiagnosed or overlooked if careful evaluation is not made. 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.