This report describes the case of a 40 year old woman with a giant left atrial myxoma. Only a thin path of 9 mm diameter allowed blood flow through the left atrial chamber to the left ventricle. Despite this obstruction, the patient developed only minimal symptoms. Echocardiography, especially transoesophageal mode is the diagnostic procedure of choice to detect these tumours. The giant mass was successfully removed and the patient is doing well two years after surgery.