Objective: To investigate the diagnosis and treatment strategies for cholecystoduodenal fistula complicated with gallstone ileus. Methods: This study retrospectively analyzed clinical data from 19 patients with cholecystoduodenal fistula and gallstone ileus treated at Jiangsu Provincial People""s Hospital from October 2019 to October 2024. Results: Among the 19 patients (9 males and 9 females), the median age was 76 years (range 58–89). All patients presented with abdominal distension and pain, with a history of cholelithiasis spanning several years. After imaging confirmation, individualized surgical approaches—including enterolithotomy, single- or two-stage cholecystectomy, and fistula repair—were performed based on stone characteristics and patient status. Postoperatively, two cases developed incision infections, while all others recovered and were discharged without mortality. Conclusion: This study demonstrates that cholecystoduodenal fistula with gallstone ileus is clinically rare, manifests with complex presentations, often involves multiple complications, and carries high perioperative risks. Personalized treatment strategies should be tailored to individual patient conditions.