<p>Postoperative chylothorax is a rare complication after thoracic surgery, characterized by the pathological accumulation of chyle within the pleural space. The management of chylothorax remains controversial, particularly in cases that do not respond to conservative treatment strategies. This case series aims to evaluate the application of magnetic resonance thoracic ductography (MRTD) in guiding precise surgical treatment for refractory postoperative chylothorax. We retrospectively analyzed four patients with postoperative chylothorax who did not respond to conservative therapy. All patients underwent preoperative MRTD to identify the site of the thoracic duct fistula, followed by targeted ligation based on imaging findings. MRTD successfully visualized the fistula in all cases. Under this guidance, all patients underwent successful surgery, with rapid reduction in chyle output postoperatively. Chest tubes were removed within three days, and no recurrence was observed during short-term follow-up. This series demonstrates that preoperative MRTD is an effective, non-invasive imaging tool that provides essential anatomical guidance for precise surgical management of refractory postoperative chylothorax, potentially improving the targeting and success rate of the procedure.</p>