We here in present 23 thymoma cases which were operated on in Istanbul Faculty of Medicine, Department of Thoracic and Cardiovascular Surgery, between 1975-1987. The mean age was 34 (12-46) and male to female ratio was 13:10. 19 of twentythree cases were also myasthenic. Five of these 23 cases found to be malignant in character in which radiotherapy and chemotherapy were added to surgical procedure. Our operative results and follow-up were also discussed.