This chapter discusses endovascular therapy of venous thromboembolism. Anticoagulation therapy and stockings had been considered as the basic standard treatment of venous thromboembolism (VTE), which comprises deep vein thrombosis (DVT) and pulmonary embolisms (PE). This chapter covers the catheter-based treatment modalities, catheter interventions with thrombolysis, catheter interventions without thrombolysis, and recommendations on interventional treatment. The principal mechanism of catheter-based therapy is to either dissolve and/or directly remove the thrombus from the site of thrombosis. Catheter interventions with thrombolysis are the most commonly-used techniques for the treatment of patients with PE and DVT.