not-yet-known not-yet-known not-yet-known unknown Introduction Bronchial cyst is a common benign disease, often found near the trachea, bronchus, hilar and pericardium, and 90% of them are located in the middle and upper mediastinum, while thin-walled bronchial cysts located in the posterior mediastinum can be frequently encountered in clinical work, and infected thick-walled cysts are relatively rare, and the cyst wall is not clearly delineated from the esophageal epithelium, which makes the surgery somewhat difficult. Now, we summarize a case of infected thick-walled bronchial cyst in the posterior mediastinum treated by our department in order to analyze its clinical characteristics and discuss the surgical treatment experience.