Our objective was to assess efficacy and tolerance of thrombolysis using 0.6 mg/kg of Alteplase in patients with massive pulmonary embolism defined as the association of a pulmonary embolism with shock. We retrospectively included 21 patients presenting with a massive pulmonary embolism confirmed by either scintigraphy or spiral computed tomography. Patients were treated on the basis of a standard rationale followed by thrombolysis with 0.6 mg/kg Alteplase over a period of 15 minutes. Hospital mortality, vital signs before and 2 hours after thrombolysis, and incidence of hemorrhagic events were recorded. Five patients (23.8%) died, 4 of these deaths occurred during the first 4 hours after hospital admission. Systolic and diastolic blood pressure (Sp02) were significantly improved 2 hours after the beginning of thrombolysis. Five minor hemorrhagic events occurred. This study demonstrates that for patients with pulmonary embolism and shock, a bolus treatment with Alteplase is potentially effective and well tolerated.