Background <p>Extrahepatic bile duct injuries following penetrating abdominal trauma are rare, occurring in only 1–5% of cases, and are frequently missed during the initial assessment due to nonspecific clinical and imaging findings. We report a rare transfixing injury of the common bile duct caused by a stab wound, highlighting the diagnostic challenges and surgical decision-making required to prevent severe biliary complications. </p> Case presentation <p>A 35-year-old male presented two hours after a stab wound to the right hypochondrium. He was hemodynamically stable, with leukocytosis and mild anemia. A CT scan revealed a 4-cm laceration of hepatic segment IVb with moderate intra-abdominal fluid. Initial conservative management was attempted, but six hours later, he developed fever, tachycardia, and peritoneal irritation, prompting diagnostic laparoscopy. Bilious fluid was observed, and a transfixing liver laceration was identified. Conversion to laparotomy revealed a transfixing injury of the supraduodenal segment of the common bile duct. The posterior defect was repaired via the anterior defect after controlled longitudinal enlargement, a 12 Fr T-tube was placed, and a subhepatic drain was positioned. Postoperative course was uneventful. T-tube cholangiograms performed on postoperative day 8 and 60 days later showed no leakage or stricture. At 1-year follow-up, the patient remained asymptomatic.</p> Conclusions <p>Early diagnostic suspicion and timely surgical exploration are essential in penetrating upper abdominal trauma to prevent missed bile duct injuries. Primary repair with T-tube drainage may represent a safe and effective option in selected patients when tissue viability and injury characteristics are favorable.</p>