Background <p>Duodenal stump leakage (DSL) is a fairly uncommon but dangerous complication after gastrectomy with Billroth II (B-II) or Roux-en-Y (R-Y) reconstruction. The significance of reinforcing the duodenal stump to prevent DSL during laparoscopic gastrectomy is still under debate. We aimed to explore the clinical impact of duodenal stump reinforcement after laparoscopic gastrectomy with duodenal stump.</p> Methods <p>We retrospectively collected consecutive patients with gastric cancer from our center between June 2019 and September 2023. Patients who underwent laparoscopic distal or total gastrectomy (LDG or LTG) with R-Y reconstruction or B-II + Braun’s anastomosis were included in this study. The clinical and pathological characteristics of patients, their surgical parameters, and postoperative complications were compared.</p> Results <p>All the qualified patients were divided into the reinforcement group (<i>n</i> = 303) and the non-reinforcement group (<i>n</i> = 71). Duodenal stump leakage occurred in 6 (1.6%) of 374 patients. Compared to the non-reinforcement group, the incidence of DSL was significantly decreased in the reinforcement group (0.7% vs.5.6%, <i>p</i> = 0.003). The reinforcement group experienced a shorter postoperative duration of stay than the non-reinforcement group (<i>p</i> = 0.002). No statistical differences were observed in terms of overall complications. However, there were significant differences in severe (grades III and IV) complications (<i>p</i> = 0.001).</p> Conclusion <p>Duodenal stump reinforcement can reduce the incidence of DSL after laparoscopic gastrectomy with R-Y reconstruction or B-II + Braun’s anastomosis. Patients with duodenal stump reinforcement had better outcomes, compared to those without duodenal stump reinforcement. But for certain patients who have difficulty with reinforcement, the reinforcement method should be individually selected based on the circumstances, which deserves further research.</p> Graphical abstract <p></p>