The treatment of a massive or fulminant pulmonary embolism (PE) occurring in the early postoperative phase by embolectomy or fibrinolysis with streptokinase (SK) or urokinase (UK) differs with regard to success and mortality. Embolectomy has a higher mortality and is not practicable in every hospital. Fibrinolysis differs according to substance (SK or UK), dosage, and duration. Five days after extirpation of a leiomyosarcoma--located retroperitoneally in the pelvis--a 72-year-old woman had a massive PE (scintigraphy diagnosis) (Fig. 1). On PEEP-breathing, nitroglycerin (66 micrograms/min), and dobutamin (416 micrograms/min), paO2 and SaO2 showed an increasing tendency, but 4 days after the diagnosis of PE--on the 8th postoperative day--paO2 and SaO2 dropped again (Fig. 3). Fibrinolysis was undertaken with 1.5 million units of SK over a period of 40 min through a Swan-Ganz catheter located in the pulmonary artery. A few hours after the fibrinolytic treatment, paO2 increased at a significant rate and FIO2 could be markedly reduced from 0.7 to 0.4. Twenty-four hours after SK lysis the pulmonary artery pressure (PAP) had still not decreased, but the cardiac output (CO) showed an increasing tendency. The scintigraphic control 17 days after the diagnosis of PE (Fig. 2) correlated with the clinical parameters. The patient was discharged. High-dose ultra-short fibrinolysis with SK in the early postoperative period is discussed in connection with efficiency and bleeding complications ("plasmin-lysis" versus "activator-lysis").