Massive pulmonary embolism associated with cardiac arrest has an extremely high mortality in spite of cardiopulmonary resuscitation maneuvers. An early diagnosis of pulmonary embolism as cause of cardiac arrest and a rapid specific therapy able to obtain a restoration of pulmonary flow can improve the prognosis. The authors report a case of cardiac arrest for massive pulmonary embolism promptly diagnosed by echocardiography and treated by thrombolytic therapy with an initial favourable outcome.