The authors report the case of a 63-year-old woman with occlusive thrombosis of a mitral valve prosthesis and cardiogenic shock successfully treated by systemic thrombolytic therapy. This treatment was given despite metastatic hepatic and bone breast cancer. This, and other recently reported cases, argues in favour of widening the indication of thrombolysis as treatment of first intention in cases of obstruction of atrioventricular valve prostheses. Nevertheless, the relative safety of surgical treatment and the risk of systemic thromboembolism of thrombolysis, incites caution and reservation of medical therapy for carefully selected patients.