Endoscopic ultrasound (EUS)-guided hepaticogastrostomy (HGS) is widely performed not only as an alternative to transpapillary biliary drainage, but also as primary drainage for malignant biliary obstruction. For anatomical reasons, this technique carries an unavoidable risk of mispuncturing intrahepatic vessels. We report a technique for troubleshooting EUS-guided portal vein coiling to prevent bleeding from the intrahepatic portal vein after mispuncture during interventional EUS. EUS-HGS was planned for a 59-year-old male patient with unresectable pancreatic cancer. The dilated bile duct (lumen diameter, 2.8 mm) was punctured with a 19-gauge needle, and a guidewire was inserted. After bougie dilation, the guidewire was found to be inside the intrahepatic portal vein. Embolizing coils were placed to prevent bleeding. Embolization coils were successfully inserted under stabilization of the catheter using a double-lumen cannula with a guidewire. Following these procedures, the patient was asymptomatic. Computed tomography performed the next day revealed no complications.