Heritable thrombophilia as a concept in hemostasis has been continuously discovered parallel to the knowledge on physiology of bleeding disorders. Since the 1980s it has become increasingly popular to search for thrombophilia in patients with thromboembolism and their relatives. Although initially no direct evidence existed for any advantage for the patients, successive clinical studies have helped to understand the risk of thrombosis and to stratify the patients in relation to the thrombophilic defect. In the meantime national and international guidelines have been published, suggesting which candidates should be examined and what tests should be performed. In the present paper we summarise and explain the rationale of these guidelines from the european point of view.