Objective: to prospectively compare the surgical outcome of using endovenous laser ablation (EVLA) and mechanochemical ablation (MOCA) in management of patients with primary varicose veins (VV). Methods: The present study prospectively recruited 100 patients with primary VV. They were randomly and equally allocated to one of two treatment group: the EVLA group (n ¼ 50) or the MOCA group (n ¼ 50). Before intervention, all patients underwent to clinical and ultrasound assessment of the vascular system. The Venous Clinical Severity Score was used to assess clinical severity. In addition, patients completed the Chronic Venous Insufficiency Questionnaire. The primary study outcome was treatment success. After intervention, patients were followed up at 1 week, 1 months, 6 months, and 12 months. Results: Operative success was achieved in all patients. The MOCA group had a significantly shorter operative time when compared with EVLA group. The Venous Clinical Severity Score significantly improved in both groups over the follow-up period and showed significantly lower levels in the MOCA group. Perceived pain was significantly improved in both groups postoperatively with no significant differences. The Chronic Venous Insufficiency Questionnaire was significantly improved after 12 months of operation without significant differences between groups. MOCA patients had significantly lower rate of postoperative phlebitis and significantly shorter time to return to work. Conclusions: MOCA for primary VV is a feasible, effective, and safe procedure with better clinical outcome and lower rate of postoperative phlebitis when compared with EVLA