Abstract: To investigate the clinical diagnosis and treatment of thymic cysts. Methods: From January 1960 to June 2007, 16 cases of thymic cysts were treated with resection, including 5 males and 11 females with an average age of 46.6 years (22-78 years).The course of thymic cysts was 2 days to 2 years, and the average course was 99.8 days. Results: Of all the patients, 15 cases underwent complete resection, and one case received partial resection.No complications were observed.The follow up duration ranged from 4 months to 10 years, and no recurrence was observed during this period. Conclusion: Thymic cysts are benign tumors of the mediastinum and are easily misdiagnosed.Thymic tissues seen in the specimen is the criteria for pathological diagnosis of thymic cysts.Complete resection can cure thymic cysts.