Duodenal stump leakage is one of the most challenging complications following gastric resection, leading to significant morbidity and mortality. Despite advances in surgical techniques and postoperative care, managing this condition remains a critical concern for surgeons. In this chapter, we analyze the risk factors contributing to duodenal stump leakage after gastric resection, explore potential preventive measures to reduce its incidence, and describe strategies for treating this serious complication.