Background <p>The management of locally advanced rectal cancer primarily involves total mesorectal excision (TME) following neoadjuvant chemoradiotherapy (nCRT). However, the benefits of additional lateral lymph node dissection (LLND) remains controversial. This study was conducted to assess the impact of LLND on postoperative urogenital function and surgical outcomes in this patient population.</p> Methods <p>Eleven studies involving 2,069 patients were included. Relevant studies were retrieved from databases including Cochrane Library, Embase, PubMed, and Web of Science. The outcomes were presented as weighted mean differences (WMDs) or odds ratios (ORs) with 95% confidence intervals (CIs). Heterogeneity was evaluated using the I² statistic and Cochrane’s Q test. When significant heterogeneity was detected (I² ≥ 50% or P ≤ 0.05), a random-effects model was employed; otherwise, a fixed effects model was utilized.</p> Results <p>Compared to nCRT and TME alone, the addition of LLND was associated with a significantly higher risk of urinary dysfunction (OR = 5.94, 95% CI: 2.91–12.13, P &lt; 0.001), particularly in patients with a body mass index (BMI) ≥ 25&#xa0;kg/m² (OR = 10.18, 95% CI: 2.09–49.62, P = 0.004). The risk of sexual dysfunction was also increased. Although a trend toward reduced local recurrence (LR) and lateral local recurrence (LLR) was observed in the LLND group, the differences were not statistically significant. Similarly,&#xa0;no significant differences were observed in 5-year overall survival (OS) or disease-free survival (DFS).</p> Conclusions <p>LLND increases the risk of urinary dysfunction in rectal cancer patients undergoing TME after nCRT, with a notably higher risk of urinary complications in patients with BMI ≥ 25&#xa0;kg/m². Therefore, surgical decision-making should emphasise personalised approaches, particularly for overweight patients.</p>