Background: Thymus is essential in creating some of the disorders and diseases. Treatment of these disorders (particularly tumors and myasthenia gravis) is possible with complete removal of the thymus.

Materials and Methods: In this retrospective study over a period of eleven years, all case of thymectomy performed at the Department of Thoracic Surgery of shahid Beheshti University has investigated. Variables examined included age, sex, primary diagnosis, surgical technique, complications and results of surgery.

Results: The total number of patients was 50 (46% male and 54% female) with a mean age of 85.14 ± 46.41 years. Primary diagnosis was myasthenia gravis in 40% of patients and thymoma in 42% of them. Myasthenic symptom was the most common presenting symptom (50%). Radical thymectomy surgery was performed in 64% of patients. Fever and atelectasis (10%) and respiratory failure (12%) were the most common postoperative complication and mortality rate was 4%. Thymoma (64%) and thymus hyperplasia (20%) were the most frequent pathology. Clinical symptoms were gone or greatly reduced in 40% of patients. The majority of them had a primary diagnosis of myasthenia gravis (36%). 50% of patients have been followed up. The mean follow-up time in these patients is 32.20 ± 36.41 months.

Conclusion: Thymectomy surgery with low morbidity and mortality, provides the possibility of treatment of thymic lesions. Especially Thymoma and Myasthenia Gravis