Abstract： Objective To explore the optimal timing and treatment of acquired Lutembacher’s syndrome. Methods Sixteen acquired Lutembacher’s syndrome patients were studied retrospectively based on records collected between January 2000 and December 2009 in Beijing Anzhen Hospital. There were 9 males and 7 females at age of （39.45±10.23）years. All of them underwent endotracheal intubation, intravenous general anesthesia, and cardiopulmonary bypass. All patients were operated on through a median sternotomy incision into the chest, the right atrium, atrial septal defect to expand with mitral valve replacement and atrial septal defect repair. Postoperative mortality and perioperative complications were observed. During follow-up, periprosthetic leakage was observed using echocardiography, along with the level of residual atrial septal shunt, ventricular size, pulmonary artery pressure changes, and improvement in cardiac function. Results Two of the 16 patients（12.5%）died, one of renal failure, and one of respiratory failure. One patient required extracorporeal membrane oxygenation for 3 days, one required continuous renal replacement therapy for 11 days because of acute renal failure, and one experienced respiratory failure and used a respiratory machine for 23 days. All three of those patients recovered. Fourteen patients were followed up for between six months and five years, and the follow-up rate was 100%. The left ventricular end-diastolic diameter was （42.1±5.7） mm, as measured by echocardiography six months post-operation. There was no detectable periprosthetic leakage or residual shunt. The ejection fraction was （67.4%±6.7%）, and estimation of pulmonary artery pressure was （23.4±5.4） mm Hg. Twelve patients were class Ⅱ（ New York Heart Association） and two patients were class Ⅲ. Conclusion Acquired Lutembacher’s syndrome should be treated promptly if patients’ left ventricular end stage diastolic volume index is good enough to ensure they can tolerate surgery. Extracorporeal membrane oxygenation （ECMO）should be used early in patients who are anticipated to be difficult to withdraw from extracorporeal circulation perioperatively.