Fifteen iatrogenic femoral pseudoaneurysms failed ultrasonography (US)-guided compression treatments. Despite concomitant antiplatelet or anticoagulation treatment, the 15 pseudoaneurysms were successfully and definitively treated without complication with US-guided thrombin injection. Results in this preliminary study suggest US-guided thrombin injection is a safe, expeditious, low-cost, and comfortable definitive treatment for femoral pseudoaneurysms that has advantages over both US-guided compression and open surgical repair.