Methods: Consecutive patients with varicose veins and primary GSV reflux will be randomized to Electrocoagulation or Radiofrequency endovenous treatment. The primary outcome measure will be GSV occlusion rate at 3 and 6 months after treatment verified by Duplex Scanning (DS). Secondary outcome measures will be pain visual analogue scale (VAS), bruising, neuropathy and vein thrombosis frequency in the immediate postoperative period (1 week); and Clinical Etiology Anatomy and Pathophysiology (CEAP) classification ,Venous Clinical Severity Scale (VCSS), and Aberdeen Varicose Vein Questionnaire (AVVQ), obtained preoperatively, at 3 and 6 months postoperatively. For statistical analysis, we will use the Student's t test, the Mann-Whitney test and Pearson's correlation, considering positive statistical significance when level of p <0.05.