A 4-month-old infant with cyanosis but without other abnormal cardiac findings is presented in whom the diagnosis of anomalous systemic venous connection to the left atrium was made by contrast echocardiography. The diagnosis was later confirmed by cardiac catheterisation and selective cineangiography. When saline was injected into a vein on the dorsum of each hand while echocardiographically recording the cardiac structures, the left atrium, left ventricle, and aorta were opacified without visualisation of the right ventricle. Similar study with injection into the right foot produced opacification of the right ventricle without visualisation of the left-sided structures. These data suggested normal drainage of the inferior vena cava with anomalous connection of the superior vena cava to the left atrium. A review of the previously reported cases of anomalous connection of the right superior vena cava to the left atrium is presented together with the possible embryological origin of this anomaly.