Purpose: Transurethral resection of bladder tumour (TURBT) is done under general anaesthesia (GA) with muscle relaxation to prevent obturator jerk and bladder perforation. TURBT under spinal anaesthesia (SA) with obturator nerve block (ONB) may prevent the obturator jerk while eliminating the disadvantages of GA. Objectives: To assess the outcome of TURBT under SA and ONB. Methods: Patients undergoing TURBT for lateral wall tumours from 01.11.2017 to 30.10.2020 were prospectively studied. Anterior branch of obturator nerve with plain Bupivacaine was blocked with the guidance of an ultrasound scan and a nerve stimulator. Significant obturator jerk which necessitated conversion to GA was defined as failed ONB. Results: Out of 72 patients with mean age of 66.7 years underwent ONB, 61 (84.7%) were men. Fifty two (72.2%) had unilateral and 20 (27.8%) had bilateral blocks. Sixty one (84.7%) patients had no obturator jerk whereas 5 (7%) had a mild jerk which did not preclude safe resection. Six patients (8.3%) had a failed ONB requiring conversion to GA. None had a bladder perforation requiring laparotomy, developed neurovascular injury or anaesthetic toxicity and only one patient required intensive care monitoring. Conclusion: SA with anterior branch of ONB is an effective and safe alternative to GA with muscle relaxation for TURBT although a randomized trial is necessary to determine the true efficacy and safety over the other.