The obstruction of the mechanical valve prothesis (OMVP) is a serious complication. The treatment of this complication was classically surgical. Recently, the thrombolytic treatment was introduced as an alternative approach for patients with high perioperative risk and for those in whom the mechanism of the obstruction is a recently formed thrombus. The authors report four cases of OMVP treated by a thrombolytic agent (Streptokinase, SK, Streptase). Immediate success was obtained in all theses four cases. One late recurrence with fatal issue was noted. All four prostheses were Saint Jude medical (SJM), three in mitral and one in aortic position respectively. The details of the clinical presentation (acute or progressive dyspnea) as well as the contribution of the echocardiography to the diagnosis were presented. The evolution of this therapeutic approach and the international recommendations were reviewed.