Objective The perioperative safety and survival benefits of lateral lymph node dissection in elderly patients have been less reported. This study aimed to compare short-term and survival outcomes of total mesorectal excision and total mesorectal excision + lateral lymph node dissection in elderly patients. Methods A total of 444 elderly patients (>= 65 years) with middle-low rectal cancer were enrolled in three institutions and divided into the total mesorectal excision + lateral lymph node dissection group (n = 110) and the total mesorectal excision group (n = 334). Eighty-three matched pairs were selected for evaluation after propensity matching. Data of 297 patients (age <65 years) with middle-low rectal cancer who underwent total mesorectal excision + lateral lymph node dissection were also collected and reviewed. Clinical and pathological features, postoperative outcomes and survival data were collected and analyzed. Results Compared with the total mesorectal excision group, the operation time of patients in the total mesorectal excision + lateral lymph node dissection group was significantly longer (277.6 vs. 171.4 min, P < 0.001), and the estimated blood loss was significantly more (119.6 vs. 57.5 ml, P = 0.014). Although there was no significant difference in overall complications (24.1% vs. 14.4%, P = 0.115) and grade 3-5 complications (9.6% vs. 7.2%, P = 0.576) between the two groups, the incidence of urinary retention (10.8% vs. 2.4%, P = 0.029) was higher in the total mesorectal excision + lateral lymph node dissection group. Two groups of patients achieve a similar 3-year overall survival (92.8% vs. 85.4%, P = 0.195) and 3-year disease-free survival (81.5% vs. 73.0%, P = 0.625). In addition, we compared long-term outcomes in 110 elderly patients with total mesorectal excision + lateral lymph node dissection and 297 non-elderly patients with total mesorectal excision + lateral lymph node dissection, and the results showed that 3-year (89.2% vs. 80.9%, P = 0.546) and disease-free survival (76.4% vs. 70.4%, P = 0.346) were similar between elderly and non-elderly patients. Conclusions Although urinary retention is closely related to the implementation of lateral lymph node dissection in elderly patients, total mesorectal excision with lateral lymph node dissection could be performed safely with accepted overall and grade 3-5 postoperative complications in elderly patients with rectal cancer. Moreover, elderly patients with clinical lateral lymph node metastasis can also benefit from lateral lymph node dissection as well as younger patients. Prospective studies with large sample sizes are needed to verify our results further. This study shows that although urinary retention is closely related to the implementation of lateral lymph node dissection, lateral lymph node dissection could be performed safely with accepted morbidity in elderly patients with rectal cancer.