Introduction. The purpose of the study was to assess the effectiveness of endovascular mechanochemical ablation of the Great Saphenous vein and the Small Saphenous vein (GSV/SSV) using the use of Flebogrif® catheter and method, based on results obtained from the analysis of 200 patients. Material and methods. 200 patients underwent mechanochemical ablation using the Flebogrif® technique, of the 200 patients, 172 patients experienced insufficiency of the GSV and 28 experienced insufficiencies of the SSV. Follow-up assessment was established by outpatient appointments at 1, 3, 6, and 12 months postoperatively. During each subsequent visit, the result of the procedure was evaluated with the use of ultrasound. Furthermore, the intensity of clinical manifestations was assessed with the use of VCSS, CEAP, VASP scales. Any complications were also noted. Results. During 12-month follow-up the number of participants decreased to 168 (152 female, 16 male). Complete closure of the vein was achieved in 154 patients (140 female, 14 male). According to adopted criteria, 15 cases of recanalization were detected (10 complete and 5 partial). Based on the obtained results the effectiveness of the method was assessed at 92%. Conclusions. The statistical analysis of the 12-month follow-up data allowed us to conclude the following the procedural method had 92% of effectiveness at 12-month follow-up, vein diameter was not a significant limitation for the application of the technique, there was a low rate of serious complications, and adverse cosmetic effect was minimal. However , the method requires further long-term follow-up to allow for a complete assessment.