In the last ten years, several risk factors that increase the risk of venous thrombosis have been discovered. Venous thrombosis is a multicausal disease in which several risk factors, both genetic and acquired, have to occur simultaneously to cause thrombosis. This means that most individuals with single thrombophilia are asymptomatic. Although testing thrombosis patients and their relatives for thrombophilia factors seems important for tailoring the duration of (prophylactic) anticoagulant therapy or estimating the risk of recurrence of thrombosis, current data do not support screening for thrombophilia. The risk of recurrences or the duration of anticoagulant therapy are generally not altered by thrombophilia. Future research should focus on identifying clusters of thrombosis risk factors to better estimate the individual risk of thromboembolic events.