Overall 25,095 cases of general thoracic surgery were analysed, which were performed by 48 institutes in Korea during recent 6 years[242 hospital-years]. The proportions of tumorous disease and infectious disease to be operated were 6,864 cases[27.4%] and 6,775 cases [27.0%], The most common organ involved for operation was lung-bronchus 16,542 cases [69.5%], and remainders were pleura 2,500 [10.0%], esophagus 2,433[9.7%], mediastinum 1,902[7.6%], chest wall 1,297 [5.2%], and diaphragm 421 [1.7%] in order. Among 6,864 cases of tumorous diseases, the most common causes for operation were lung-bronchus tumor 3132 cases [45.6%] and most of them were lung cancer 2,731 cases [88.7%]. In the 2,019 cases of primary lung cancer with known cell type, squamous cell carcinoma 1,296 cases [64.2%] and adenocarcinoma 460 cases [22.8%] were the most. The common types in the 1,207 cases of mediastinal tumor with known cell type were neurogenic tumor 348 cases [28.8%], thymoma 311 [25.8%], and teratoma 252[20.9%]. The annual cases of operation for tumorous disease including malignant tumor were increased steadily. Operation for infectious lung diseases [including bronchiectasis and tuberculosis] were about twice common than infectious pleural disease [i.e. empyema], and operations for tuberculous disease occupied about half cases of infectious lung disease. In 11,456 cases of other disease entities, excluding tumorous and infectious disease, there were bullous lung disease 9,074 cases[79.2%], benign esophageal disease 484[4.2%], myasthenia gravis 356[3.1%], chest wall deformity 483[4.2%], and diaphragmatic lesion 421[3. 7%] in order. We propose that above results for inquiry can be used as the basic data of general thoracic surgery in Korea.