In spite of many advances in medicine, anesthetic technique and surgical managements, pulmonary problems are the most frequent postoperative complication, particularly after abdominal surgery. As postoperative pulmonary complications, atelectasis, pleural effusion, pneumonia, chronic bronchitis and lung abscess can be occured. This study include evaluation of chest films of 2006 patients (927 male, 1079 female), who had been operated abdminal surgery form Jan. 1979 to June, 1980 in the Hanyang university hospital. The results were as follows ; 1. 70 cases out of total 2006 cases (3.5%) developed postoperative chest complications, 51 cases(5.5%)in male, 19 cases (1.8%)in female. 2. The complication rate was increased according to the increased of age. The incidence of the postoperative complications over 40 years of age was higher than the overall average complication rate. 3. The most common postoperative pulmonary complication was pleural effusion, next pneumonia, atelectasis and pulmonary edema respective .The complication rate of the group of upper abdominal surgery is much higher than the group of lower abdominal surgery. 5. Complication rate increases according to increase of the duration of operation. 6. There were significant correlations between the operation site and side the complicated hemithorax.