Objective: To investigate the success rate, duration of surgery, and complications of simultaneous bilateral mechanical endoscopic dacryocystorhinostomy (EN-DSR) operation. Methods: This retrospective study included twenty-eight eyes of 14 patients who presented with bilateral nasolacrimal duct obstruction and underwent simultaneous bilateral mechanical EN-DCR operation. In addition to the operation times of each eye, anatomical and functional success rates and complication rates at the 1st week, 1st month, 3rd month, and 6th-month follow-ups were evaluated. Results: The mean age of the patients was 51.0 ± 8.5, and the female/male sex ratio was 9/5 [64.3%/35.7]. The mean operation time for both eyes was 73.93 ± 7.64 minutes (min-max: 60-90). Anatomical success rates were found to be 100%, 96.4%, 92.9%, and 92.9% for the 1st week, 1st month, 3rd month, and 6th month, while the functional success rates were 96.4%, 96.4%, 92.9%, and 89.3%, respectively. Postoperative complications were hematoma in the lacrimal sac region in 4 eyes (14.3%), epistaxis that could be controlled with simple intervention in 2 eyes (7.1%), and silicone tube extrusion in the early period of 1 week in 2 eyes (7.1%). There was no significant difference between the right and left eyes in terms of surgery time, anatomical and functional success rates (respectively, p=0.130, p=0.142, p=0.541). Conclusion: Simultaneous bilateral mechanical EN-DCR is a method that can be recommended in patients with bilateral nasolacrimal duct obstruction, with short surgical time, high success, and low complication rates.