Duodenal stump fistula (DSF) is a dangerous complication after gastrectomy. There is no consensus on the management of DSF. Sometimes, emergency surgery may be necessary. We present the case who underwent subtotal gastrectomy with Roux-en-Y reconstruction for advanced gastric cancer. After that surgery, we diagnosed DSF due to pancreatic fistula, and performed reoperation because of hemodynamic instability due to diffuse peritonitis and sepsis. We resected the stump and closed with handsewn suturing and inserted three intra-abdominal drainage tubes, including a dual drainage tube around the duodenal stump. Although there was a recurrence of DSF, because of the continuous and absolute drainage, the patient improved and discharged on postoperative Day 59. From this experience, diligent debridement and a continuous suction dual drainage system, intraluminal drain of the duodenum, and biliary diversion may be an effective surgical management for DFS.