We have experienced 47 cases of primary mediastinal tumors & cysts in the Department of Thoracic and Cardiovascular Surgery, Chonbuk National University Hospital, from September, 1979 to November, 1990. The results were as follows: 1. The age distribution was from 6 months to 69 years old and the mean age was 32.3 years old. Of all 47 primary mediastinal tumors and cysts, 21 patients were male and 26 patients were female. 2. The neurogenic tumors[11 cases, 23.4%] were most frequently encountered and followed by thymoma[10 cases. 21.3%] and teratodermoid[9 cases, 19.1%]. 3. The anterosuperior mediastinum[59.6%] was most common tumor location, and followed by posterior mediastinum[25.6%], middle mediastinum[14.9%]. 4. The most common tumors were thymoma and teratodermoid at anterosuperior mediastinum, benign cyst at middle mediastinum, and neurogenic tumor at posterior mediastinum 5. The malignant tumors were 10 cases[21.3%] of the 47 cases and they were all symptomatic. 6. The most common chief complaint at admission was chest pain or discomfort[34%], and followed by coughing[23.4%], and dyspnea[17%]. 7. The successful complete removal was done in 37cases of benign tumors and cysts. In malignant cases, the surgical intervention was done in 3 cases, and 6 cases were treated with irradiation and chemotherapy, and 1 case was only biopsied. 8. The postoperative complications were developed in 7 cases[14.6%]. There was no case of hospital mortality.