Despite optimal treatment of acute deep-vein thrombosis (DVT) there is a great chance of recurrent DVT and development of post-thrombotic syndrome (PTS) in the long term. The degree of spontaneous recanalization differs per patient and per thrombus location. 90% of all femoropopliteal occlusions will fully recanalize within 1 year; however, in the case of an iliofemoral thrombosis, recanalization occurs only in a minority of cases. Post-thrombotic complications occur more often following iliofemoral thrombosis, and the chance of recurrent thrombosis is greater than following thrombosis in a more distal location. An anatomical variation or abnormality also more often underlies an iliofemoral thrombosis. It is important to identify patients with a greater chance of developing PTS promptly and to treat them in order to prevent post-thrombotic damage. There are still insufficient trial data available to implement catheter-directed thrombolysis as standard therapy for iliofemoral thrombosis