Great saphenous vein (GSV) incompetence is the most common cause of superficial venous insufficiency. Radiofrequency catheter ablation (RFA) is superior to conventional ligation and stripping, and endovenous laser treatment (EVL) has emerged as an effective alternative to RFA. This randomized study evaluated RFA and EVL for superficial venous insufficiency due to GSV incompetence and compared early and 1-year results. Between June 2006 and May 2008, patients with symptomatic primary venous insufficiency due to GSV incompetence were randomized to RFA or EVL. Patients with bilateral disease were randomized for treatment of the first leg and received the alternative method on the other. Pretreatment examination included a leg assessment using the Venous Clinical Severity Score (VCSS) and CEAP classification. Patients completed the Chronic Venous Insufficiency Questionnaire 2 (CIVIQ2). RFA was performed with the ClosurePlus system (VNUS Medical Technologies, Sunnyvale, Calif). EVL was performed with the EVLT system (AngioDynamics Inc, Queensbury, NY). Early (1-week and 1-month) postoperative results of pain, bruising, erythema, and hematoma were recorded. Duplex ultrasound (DU) imaging was used at 1 week and 1 year to evaluate vein status. VCSS scores and CEAP clinical class were recorded at each postoperative visit, and quality of life (QOL) using CIVIQ2 was assessed at 1 month and 1 year. The study enrolled 118 patients (141 limbs): 46 (39%) were randomized to RFA and 48 (40%) to EVL, and 24 (20%) had bilateral GSV incompetence. At 1 week, one patient in the RFA group had an open GSV and was deemed a failure. More bruising occurred in the EVL group (P = .01) at 1 week, but at 1 month, there was no difference in bruising between groups. At 1 year, DU imaging showed evidence of recanalization with reflux in 11 RFA and 2 EVL patients (P = .002). The mean VCSS score change from baseline to 1 week postprocedure was higher for RFA than EVL (P = .002), but there was no difference between groups at 1 month (P = .07) and 1 year (P = .9). Overall QOL mean score improved over time for all patients (P < .001). CEAP clinical class scores of >or=3 were recorded in 21 RFA (44%) and 24 EVL patients (44%) pretreatment, but at 1-year, 9 RFA (19%) and 12 EVL patients (24%) had scores of >or=3 (P < .001). This represented a significant improvement in all patients compared with baseline. Both methods of endovenous ablation effectively reduce symptoms of superficial venous insufficiency. EVL is associated with greater bruising and discomfort in the perioperative period but may provide a more secure closure over the long-term than RFA.