Objective To assess the short and long-term clinical effects and safety of self-expanding metal stents combined with neoadjuvant chemotherapy in patients with locally advanced left-sided colorectal cancer with obstruction. Methods Clinical data of 56 patients with obstructive left-sided colorectal cancer at department of the general surgery in our hospital from February 2018 to December 2024 were retrospectively analyzed. The patients were divided into a stent group (n = 22) and a neoadjuvant therapy group (n = 34) based on treatment protocols. In the stent group, self-expanding metal stents were first placed via colonoscopy, followed by direct radical resection of colorectal cancer once obstructive symptoms resolved. The neoadjuvant therapy group first underwent endoscopic placement of self-expanding metal stents, followed by 2 ~ 4 cycles of chemotherapy after resolution of obstruction symptoms, then underwent radical resection of colorectal cancer. The interval time between stent placement and surgery, surgical duration, intraoperative bleeding, anastomosis method, number of lymph nodes removed, postoperative complication rate, postoperative recovery and long-term survival outcomes were compared between the two groups. Results The median interval time between stent placement and surgery was longer in the neoadjuvant therapy group than that in the sent group (P< 0. 001). There were no statistically significant differences in surgical duration or intraoperative bleeding between the two groups. The proportion of circular anastomosis in the neoadjuvant therapy group was higher than that in the stent group ( P< 0. 05). There were no statistically significant differences in the number of lymph nodes removed during surgery, the proportion of positive lymph nodes, or the incidence of postoperative complications between the two groups (P> 0. 05). Postoperative pathology showed that 8 patients (23. 5% ) in the neoadjuvant group achieved pathological response, and 22 patients (64. 7% ) achieved tumor downstaging. However, there were no statistically significant differences in 2-year overall survival rate (86. 4% vs. 86. 5% ) and 2-year disease-free survival rate (67. 0% vs. 83. 3% ) between the two groups(P> 0. 05). Conclusions Neoadjuvant therapy after stent implantation prolongs the interval to surgery, but it is beneficial to reducing the proportion of manual anastomosis and improving the safety of surgery. It also causes oncological downstaging in some patients and increases the number of lymph nodes cleared. However, it has not yet affected long-term survival.