Objective. The treatment of choledocholithiasis with duodenal stenosis is a clinical difficult problem. This study aimed to investigate the efficacy and safety of ERCP via gastroscopy in the treatment of choledocholithiasis and duodenal stenosis. Methods. From January 2015 to December 2020, 21 patients with choledocholithiasis with duodenal stenosis who underwent ERCP treatment under gastroscopy in our hospital were enrolled. The patients’ case characteristics, ERCP status, and complication rate were analyzed. Results. Among the 21 patients, 17 cases were successful in ERCP, and a total of 29 times ERCPs were performed, with an average of 1.71 times per patient. Among the failures of ERCP, selective deep intubation of common bile duct was unsuccessful in 4 cases. Six patients underwent multiple lithotomies, after the operation, of which 4 patients underwent secondary ERCP lithotomy and 2 patients underwent triple ERCP lithotomy. All patients successfully completed the balloon dilation without serious complications. Two patients developed mild acute pancreatitis after ERCP, and all recovered after medication. Conclusion. In patients with choledocholithiasis and duodenal stenosis, ERCP treatment by gastroscopy has a higher success rate and does not increase the incidence of complications, but there is a problem of cholecystolithiasis recurrence.