Abstract: In this report, we present two cases of acute left ventricular failure after large volume pericardiocentesis. Both cases presented with the symptoms of massive pericardial effusion which documented with Trans-Esophageal Echocardiography (TEE). The case No. 1 had the history of concomitant aortic and Mitral Valve Replacement (MVR and AVR), 2 months before the present admission. The case No. 2 had severe valvular PS and underwent valvotomy, PS repair and PFO occlusion, 2 weeks ago. An emergent pericardiostomy was performed for both cases and approximately 1000 mL of serous fluid was removed. However, after 2 h, the patients complained of symptoms of LV failure. High-dose inotropic support and other supportive measures were considered. The first case dead and the second survived.