Four cases of double-orifice left atrioventricular (AV) valve are reported. Three of the four patients with double-orifice left AV valve had other associated congenital heart diseases, and the fourth had double-orifice left AV valve alone. A patient with associated ventricular septal defect, who presented with pulmonary congestion and hypertension, suffered from severe heart failure. However, these symptoms improved with the spontaneous closure of the ventricular septal defect. The patient with double-orifice left AV valve alone showed no cardiac symptoms. Two-dimensional and Doppler echocardiography did not detect the double-orifice left AV valve in two of the four patients. More recently, the echocardiographic technique has allowed a noninvasive and more frequent detection of this abnormality. But both of these patients had left-to-right atrial shunt and subsequent reduced transmitral flow and left ventricular volume, which may have made it difficult to detect the morphological and hemodynamic characteristics of double-orifice left AV valve. Careful and repeated echocardiographic observation of mitral configuration is required to determine the presence of double-orifice left AV valve when heart disease is associated with a left-to-right atrial shunt.