Pulmonary embolism is a frequently observed clinical symptom. Its mortality rate is ca. 10 % und occurs mainly in the acute phasis. Immobilization, surgery, old age, malignancies, hormonal factors as well as inherited or acquired thrombophilia are important risk factors. Spiral computed tomography and ventilation-perfusion-scintigraphy are the decisive imaging methods. Pulmonary angiography is still the gold standard. The risk of pulmonary embolism could be lowered by 50 % through prophylaxis with unfractioned or low-molecular-weight heparin. The therapy of pulmonary embolism stratifies the clinical grade and reaches from ambulant therapy with low-molecular-weight heparin to thrombolysis or embolectomy in massive pulmonary embolism. Long-term anticoagulation, usually with vitamin-K-antagonists, should be applied according to the individual risk profile of the patient.