Interventional treatment of venous insufficiency has been revolutionized by endovascular techniques. Some of these techniques, and particularly thermal ablation (endovenous laser, radiofrequency) are now recommended as first-line therapy in the latest international guidelines. This is because of less post-operative pain, a shorter leave from employment and similar or lower recurrence rate. Endovenous techniques allow safer and more efficient treatment of certain particular conditions : small saphenous vein, ulcers, and recurrent varicose veins. In addition to clinical history and examination, a duplex sonography of deep and superficial veins, performed by an angiologist, is the most important exam in order to determine proper indication and best treatment strategy for each patient.