Catheter-directed thrombolysis for iliofemoral deep venous thrombosis (DVT) aims to reduce acute leg symptoms and to prevent the post-thrombotic syndrome. There are no data from controlled trials in pregnant patients. Reports of thrombolysis for treatment of DVT during pregnancy are scarce. Pregnancy is considered a relative contraindication to thrombolytic therapy because of the risk of bleeding and concerns about the effects of radiation exposure on the fetus. We report on a catheter-directed thrombolysis procedure without radiation and contrast medium exposure in a first-trimester pregnant patient with massive iliofemoral DVT and free-floating thrombus extending to the suprarenal inferior vena cava.