<p>Two emerging techniques for mid-low rectal cancer treatment include robotic surgery (RoTME), and transanal total mesorectal excision (taTME). Additionally, using the superior pelvic diaphragm as a landmark helps protect pelvic autonomic nerves and reduces intraoperative risks. This study compares the long-term oncological and functional outcomes of taTME and RoTME in cT3/cT4 patients after neoadjuvant therapy using propensity score matching, while also evaluating the role of the superior pelvic diaphragm as a surgical guide. We retrospectively analyzed patients who underwent proctectomy between February 2017 and May 2019. After applying strict inclusion criteria, propensity score matching was performed. Additionally, we identified and included patients with a difficult pelvis for further analysis. Oncological outcomes were assessed using 3- and 5-year disease-free survival (DFS) and overall survival (OS), visualized with Kaplan-Meier curves. Pelvic nerve preservation was evaluated based on urinary dysfunction, while anal function was measured using the LARS score questionnaire. 75 patients underwent taTME and 203 underwent RoTME. After 1:2 propensity score matching, the groups comprised 75 taTME and 150 RoTME patients. All patients completed 60-month oncological follow-up, with anal function assessed at six months postoperatively. Compared to RoTME, taTME showed a lower anastomotic leak incidence but higher rate of diverting stomas, despite comparable baseline data.No significant differences were observed in intraoperative complications, functional outcomes, or long-term survival. Notably, identifying the superior pelvic diaphragm intraoperatively aided pelvic nerve preservation. Both RoTME and taTME prove feasible for treating cT3/cT4 lower rectal cancer post-nCRT. When performed beyond the learning curve, these techniques represent safe and reliable surgical options.</p>