A 55-year-old woman seeks medical attention with palpitations, atypical chest pain and dyspnea upon exertion, lasting for 12 months. ECG showed left ventricular hypertrophy. Transthoracic Doppler echocardiogram confirmed hypertrophy of the left chambers and showed a quadricuspid aortic valve, with equal-sized cusps, in addition to a moderate regurgitant central flow. Upon echocardiography, the quadricuspid valve is identified by its characteristic "X" form during diastole and rectangular aspect during systole. Heart failure symptoms are presumably caused by valve insufficiency due to abnormal leaflet coaptation. Considering the possibility of progressive regurgitation, follow up on the patient was performed with periodic echocardiographic control. Symptoms responded to treatment.