Most subphrenic abscesses represent complication of the intraabodominal surgery. Suppression of the infection by wide use of antibiotics may protract the course and obscure the clinical findings. Therefore, the radiologist plays a paramount role in early diagnosis, espicially analysis of conventional radiography of fluoroscopy, simple chest and abdomen in the initial detection of subphrenic abscess, is very useful. Twenty-one patients of the clinically and surgically proven subphrenic abscess at Chosun University Hospital in the period from January 1976 to June 1982 were analyzed clinically and radiologically. The results were as follows : 1. Male to female ratio was 6 : 1 in 21 patients. Incidence was most common in the third to sixth decade of life. 2. The clinical presentation is often nonspecific and more generalized rather than fulminant and locallized because of masking effect of antibiotics. 3. In 81% of subphrenic abscesses are occured as a postoperative complications and most common cause was gastroduodenal operation. 4. Of the 21 patients, subphrenic abscess was located on the left subphrenic space in 10(48%), on the right in 8(38%), and was bilateral in 3(14%). 5. The most common Roentgenological findings were elevation of afected side hemidiaphragm and pleural effesion, or decreased diaphragmatic movement during fluoroscopy. Others include in order of frequency : Subphrenic air-fluid level, basal atelectasis, displaced adjacent organs, an dbasal infiltration.