We report a case of an iatrogenic arteriovenous fistula complicated by catheter-directed thrombolytic therapy in a patient with acute deep vein thrombosis of a lower extremity. To the best of our knowledge, this is the first report of an arteriovenous fistula between the sural artery and popliteal vein in that situation. As the vessels have a close anatomical relationship, the arteriovenous fistula seems to be a potential complication after endovascular thrombolytic therapy of acute deep vein thrombosis.