Title: Impact of Single-Day Training on Surgical Management of Choledocholithiasis in Peripheral Hospitals Introduction: Choledocholithiasis occurs in up to 20% of patients undergoing cholecystectomy. While ERCP remains the dominant treatment modality, it requires access to specialised services and is associated with additional procedures, morbidity, and hospital transfers. Laparoscopic transcystic common bile duct exploration (TCBDE) offers a single-stage alternative but is underutilised by general surgeons. This study assessed whether a single-day TCBDE training course altered management practices and outcomes in hospitals without on-site ERCP capability. Methods: A retrospective audit was conducted across two peripheral hospitals within Eastern Health, Melbourne. All patients diagnosed with choledocholithiasis between April 2024 and April 2025 were included, comparing management in the six months before and after TCBDE training of seven experienced general surgeons. Outcomes assessed included initial management strategy, length of stay, complications, stone clearance, need for transfer, and 30-day readmission. Patients with malignant obstruction, ascending cholangitis, prior cholecystectomy, or unfitness for general anaesthesia were excluded. Results: Fifty-nine patients were included (28 pre-course, 31 post-course). Pre-course, 100% underwent ERCP. Post-course, 54.8% underwent TCBDE as first-line management, with ERCP reserved for 45.2%. Mean length of stay decreased from 5.9 days in ERCP patients to 4.6 days following TCBDE. Stone clearance rates were 96.4% (pre-course ERCP), 100% (post-course ERCP), and 82.5% for TCBDE. Most patients experienced no postoperative complications. Conclusion: A single-day TCBDE training course resulted in a meaningful shift toward single-stage surgical management of choledocholithiasis in peripheral hospitals, reducing reliance on ERCP and inter-hospital transfer. These findings support broader TCBDE training for general surgeons.