Background and Aims Bile duct injuries and defects can occur during hepatobiliary surgery due to various reasons. Minor defects can be repaired by direct suturing, while more significant defects often require end-to-end bile duct anastomosis or Roux-en-Y cholangiojejunostomy. These latter procedures are more complex and end-to-end anastomosis may lead to bile leakage or bile duct stricture due to tension at the anastomotic site and issues with blood supply. Cholangiojejunostomy alters the normal physiological pathway and is associated with more complications. Therefore, seeking a safer, more effective, and simpler method for bile duct repair is necessary. This study was performed to investigate the clinical efficacy and application value of using the serosal surface of the round ligament of the liver to repair bile duct defects.Methods The clinical data of 13 patients who underwent bile duct defect repair using the serosal surface of the round ligament of the liver in 6 hospitals between May 2008 and March 2023 were retrospectively analyzed.Results Among the 13 patients, 3 were males and 10 were females, with ages ranging from 40 to 68 years (mean age 55.6 years). The underlying conditions included gallstones in 2 cases, gastric cancer in 1 case, inflammatory bile duct stricture in 4 cases, hepatocellular carcinoma in the left inner lobe of the liver in 2 cases, and other malignancies in 4 cases. Postoperative bile leakage occurred in 6 patients (46.2%), with bile leakage resolving in 5 patients within 7 to 27 d after surgery through the bile duct and abdominal drainage and in 1 patient within 56 d after the operation. There were no perioperative deaths. Cholangiography imaging was performed in 7 patients, with no signs of bile leakage, bile duct stricture, or bile duct stones observed. Two patients underwent bile duct endoscopy, showing no demarcation between the bile duct mucosa and the serosa of the round ligament of the liver. The follow-up period ranged from 3 months to 14 years. One patient exhibited mild dilatation of the left intrahepatic bile duct, possibly due to stricture at the left hepatic duct repair site, The other 12 patients showed no stricture or cystic dilatation at the repair site.Conclusion Repairing bile duct defects with the serosal surface of the round ligament of the liver has a good effect and is simple and easy to perform, which is worthy of clinical promotion and application.