Background. Bladder cancer currently poses a major challenge to urologic oncologists worldwide due to its high recurrence rates. Although the treatment of non-muscle invasive bladder cancer does not carry the same risks as the treatment of muscle invasive forms, frequent recurrences and subsequent tumor progression can lead to patients undergoing disabling organ-removing operations with great risk to life and health. Therefore, improvement of treatment methods for non-muscle invasive bladder cancer may make the quality of life of patients with these diseases better.Aim. To evaluate the safety and effectiveness of en-bloc transurethral resection of bladder tumor (eTURBT) compared with conventional TURBT (cTURBT) in the treatment of patients with non-muscle invasive bladder cancer.Materials and methods. The retrospective study included 197 patients with newly diagnosed primary non-muscle invasive bladder cancer who underwent eTURBT (n = 34) or cTURBT (n = 163) at the University Urology Clinic between 2011 and 2021. The groups did not have statistically significant differences in gender, age, and tumor characteristics. Median follow-up was 28.25 months.Results. Both groups had comparable perioperative indicators, but the quality of the material obtained after eTURBT was better than after cTURBT. Patients with adjuvant intravesical chemotherapy in the early postoperative period had better oncological results compared with patients without it (35.71 % recurrences and/or progression versus 49.12 %) (p <0.05). Additionally, in the eTURBT group the number of recurrences was significantly lower: 14.71 % versus 40.49 % (p <0.05).Conclusion. In the absence of contraindications for eTURBT, this method of surgical treatment of non-muscle invasive bladder cancer with adjuvant intravesical chemotherapy in the early postoperative period seems more promising with better oncological indicators.