 The RIETE Registry pretends the improvement of care of patients with thromboembolic disease. Very often the investigators pose serious doubts on how to manage a specific patient. Sometimes because it is a patient with thrombocytopenia, a pregnant woman, a patient with a recent cerebral bleeding or cerebral metastasis, a patient with gastroduodenal ulcer or hepatic cirrhosis. There is no clinical evidence about how the investigators should manage these patients and the investigators have to individualize its management. The bibliography available is not of much help. Only if the investigators have a database with a sufficient number of cases, they may be able to make evidence based decisions. 