Initiated in January 2008, The PE-aWARE (Pulmonary Embolism WArsaw REgistry) is an on-going single-centre prospective observational study of patients with confirmed acute pulmonary embolism (APE). Extensive data on consecutive patients with pulmonary embolism is collected and stored. The main objective is to collect and provide information on patients' characteristics, management, and outcome with the purpose of decreasing mortality in APE, the occurrence of bleeding, and the frequency of thromboembolic recurrences. Moreover, the PE-aWARE registry serves as a basis for creating predictive scores for clinicians which aid patient management. The study endpoints comprise clinically recognized (and objectively confirmed) recurrences of PE, major and minor bleeding complications classified according to the International Society on Thrombosis and Haemostasis classification, need for cardiopulmonary resuscitation or catecholamines, and death.