Background: Varicose veins surgery was evolved in the past decade. Many studies showed that Endovenous Radiofrequency Ablation (EV-RFA), a novel method for varicose veins treatment, produced complications fewer than conventional venous stripping, particularly postoperative pain and ecchymosis. There were a lot of studies reported about inflammatory response but there was few studies compare inflammatory response between procedures. This study purpose compare preoperative and postoperative level of serum Interleukin 6 (IL-6) and C-Reactive protein (CRP) to determine the inflammatory response of EV-RFA and conventional venous strip-ping. This study also compares Visual Analogue Scale (VAS) and ecchymoses between these two procedures.Methods: A prospective cohort study measuring IL-6 and CRP level at before and 24-hour after surgery in symptomatic varicose vein patients who underwent either EV-RFA or conventional venous stripping.Results: Fifty-nine patients were included, 27 patients were treated by conventional venous stripping and 32 patients were treated by EV-RFA. There was no different in demographic characteristics among two groups. Twenty-four hour postoperative level of IL-6 and CRP significantly increased (p < 0.001 and < 0.001, respectively) in both EV-RFA group (p < 0.001 and < 0.001, respectively) and venous stripping group (p = 0.043 and < 0.001, respectively) compare to pre-operative level. Increasing in 24-hour postoperative level of IL-6 and CRP in EV-RFA group was significantly lower than in venous stripping group (p < 0.001 and p = 0.045, respectively). Post-operative VAS and ecchymosis were also significantly different between EV-RFA group and ve-nous stripping group. (p < 0.001 and p < 0.001, respectively).Conclusion: EV-RFA produced inflammatory response, VAS and ecchymosis significantly lower than conventional venous stripping. ConclusionEV-RFA established lower postoperative pain and rate of ecchymosis compared to HL/VS. 24-hour postoperative level of CRP and IL-6 were also increased lower in EV-RFA group compared to HL/ VS group. This result evidenced lower rate of tissue trauma after EV-RFA.