This report is an analysis of 60 cases of primary mediastinal tumors and cysts which were experienced in chonbuk National University Hospital, Wonkwang University Hospital and Chonju Presbyterian Medical Center from january 1985 to October 1990. The result was summarized like this; 1) Age distribution was various from ages of 5 to 75 years. There were 26 males and 34 females, sex ratio of patients was 1: 1.3 (M:F). 2) The most common chief compliant was dyspnea (21 cases, 35%) and followed by chest pain, coughing and chest discomfort. 17 patients (28%) were asymptomatic. 3) The most common primary mediastinal tumor was thymoma, which comprise 28% (17 cases) of all our cases and followed by neruogenic tumor (14 cases, 23%) and germ cell tumor (11 cases, 18%). 4) The incidence of malignancy of all case was 22%; 2 cases were asymptomatic and the most common malignancy was malignant lympoma (5 cases, 38.5%). 5) The anterior mediastinum was the most common tumor location and followed by posterior and middle mediastinum. Anterior mediastinal tumors mainly consisted of thymomas and germ cell tumors and posterioc mediastinal tumors mainly did neurogenic tumors. 6) Of 60 cases, 21 cases were confirmed histopathologically by percutaneous transthoracic needle lung biopsy. 7) Of 60 cases, 40 cases were received radical tumor resection.