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 wereas follows: 1. Although all cases showed mediastinal widening by the mean 29.9%(SD 16.2), there was no case ofreoperation due to excessive mediastinal hemorrhage. 2. Among 160 cases, 87 cases (54%) showed thoracicalterations after surgery. 3. Abnormal sternal findings were radiolucent vertical line in 15 cases (9%), sternaldehiscence in 4 cases (2%), sternal osteomyelitis in 4 cases (2%). 4. The types of pulmonary parenchymal lesionswere 24 cases (15%) of atelectasis, 15 cases (9%) of pneumonia and 3 cases (2%) of pulmonary edema. 5. Pleuraleffusion was noted in 39 cases (24%). 6. Among the abnormal extra-alveolar air collections, there werepneumothorax in 10 cases (6%), pneumomediastinum and pneumopericardium in 29 cases (18%), and pneumoperitoneum in5 cases (3%). 7. In 23 cases with phrenic nerve paralysis, the involved site was left in all and the associatedpulmonary infiltration in left lower lobe was found in 82%(19/23). 8. 4 cases of cardiac tamponade developed 9 to20 days after surgery("late" form).