T-tube cholangiography and choledochoscopy are commonly used techniques for detecting residual bile duct stones after biliary surgery. However, the utility of routine cholangiography before T-tube removal needs further investigation. This study aims to evaluate the diagnostic efficacy of various methods for detecting residual calculi following biliary surgery.We retrospectively analyzed the clinical data of 287 adult patients who underwent common bile duct exploration with T-tube drainage, followed by T-tube cholangiography and choledochoscopy, at the Department of General Surgery, Xuanwu Hospital, Capital Medical University, between 2017 and 2022. Exclusion criteria were patients with bile duct tumors, incomplete medical records or loss to follow-up, and patients with contraindications to T-tube or choledochoscopy. McNemanr test and Kappa test were used to compare the results and consistency between choledochoscopy and T-tube cholangiography. All patients underwent both cholangiography and choledochoscopy six to eight weeks after laparoscopic cholecystectomy combined with common bile duct exploration and T-tube drainage. The results of T-tube cholangiography and choledochoscopy for each patient were recorded, analyzed, and compared.Among the 287 patients, T-tube cholangiography detected residual stones in 38 cases, which were confirmed by choledochoscopy in 29 cases. Conversely, of the 249 patients without evidence of residual stones on T-tube angiography, 11 patient was later found to have retained stones through choledochoscopy. There was no significant difference between the results of T-tube cholangiography and choledochoscopy (P = 0.82), indicating a high level of agreement between the two methods (Kappa value: 0.70) (95% CI, 0.65-0.76).There is no significant difference in the diagnostic accuracy between T-tube cholangiography and choledochoscopy for detecting residual bile duct stones after surgery (P = 0.82). The two methods demonstrated a high level of consistency (Kappa value: 0.70) (95% CI, 0.65-0.76). The choice of diagnostic method for postoperative residual bile duct stones should be based on the specific condition of the patient.© 2024. The Author(s).