Isolated congenital aneurysm of the left atrium with intact pericardium is a rate anomaly, which usually presents with arrhythmia, cerebral embolism or abnormalities on routine chest X-ray. Surgery is indicated in most cases to eliminate a potential source of systemic emboli and arrhythmias. A 42-year-old woman having cervical cancer, she was suspected of having a left atrial aneurysm on review of chest X-ray and confirmed by echocardiography and cardiac catheterization. Surgical resection of Left atrial aneurysm was achieved without complication using median sternotomy with cardiopulmonary bypass. The postoperative course was uneventful.