Pulmonary embolism is a frequent disease with well known acquired or hereditary risk factors. The first diagnostic step is to determine a pre-test probability of the disease based on the revised Geneva score. Further work up with D-Dimers, blood gases and ECG, will ascertain the diagnostic of the condition. The prognosis will be better evaluated with BNP and troponine. Negative D-Dimers can rule out pulmonary embolism when pre test probability of the disease is low or intermediate. Radiological work-up includes computed tomographic pulmonary angiography when D-Dimers are positive and when the pre test probability is high, or ventilation/perfusion scan in case of iodine allergy or renal failure. Finally, guidelines will help choosing which patients suffering of pulmonary embolism have to undergo a hematological assessment or oncologic screening.