this retrospective study was performed to detect thoracic changes on chest films after open-heart surgery. Authors reviewed total 160 cases who underwent median sternotomy from July 1984 to January 1988. The results were as follows; 1. Although aoo cases showed mediastinal widening by the mean 29.9%(SD 16.2) there was no case of reopera-tion due to excessive mediastinal hemorrhage. 2. Among 160 cases 87 cases (54%) showed thoracic alterations after surgery. 3. Abormal sternal findings were radiolucent vertical line in 15 cases (9%) sternal dehiscence in 4 cases(2%) sternal osteomyelitis in 4 cases(2%) 4.The types of pulmonary parenchymal lesions were 24 cases (15%) of atelectasis 15 cases (9%) of pneumonia and 3 cases (2%) of pulmonary edema. 5. Pleural effusion was noted in 39 cases (24%) 6. Among the abnormal extra-alveolar air collections there were pneumothorax in 10 cases(6%) pneumomediastinum and pneumopericardium in 29 cases (18%) and pneumoperitoneum in 5 cases (3%) 7. In 23 cases with phrenic nerve paralysis the involved site was left in all and the associated pulmonary infiltra-tion in left lower lobe was found in 82% (19/23). 8. 4 cases of cardiac tamponade developed 9 to 20 days after surgery ("late" from)uot; from)