The presence of a foreign body in the respiratory tract is a serious and, on occasion, fatal conditionl. Theearly diagnosis and removal of the aspirated material may save the patient's chronic illness, invalidation, orpossibly death. Chest X-ray plays an important role in the diagnosis of airway foreign bodies in children. This retrospective study was performed to detect the lodgement site of aspirated foreign bodies, roentgenographic findings, and changes in chesst X-ray pattern according to time interval following aspiration. We reviewed therecord and X-ray findings of 63 patients examined at the department of Radiology, Catholic University, Medicalcollege, from January 1983 to December 1988. The results are as follows: 1. The laterality of the occurrence offoreign body aspiration was right brochial tree 26 cases (41.2%), left bronchial tree 22 cases (34.9%), trachea 8cases (12.7%), coughted out 6 cases (9.5%), bilateral lower lobe broanchi 1 cases(1.6%). The relatively equalincidence of right (41.2%), and left (34.0%) sided bronchial aspiration of foreign body was noted. 2. Theroentgenographic findings after bronchial foreign body aspsiration were unilateral hyperlucent lung 32 cases(52.4%), mixed pattern 10 cases (16.3%) normal 8 cases(13.1%), atelectasis 7 cases (11.4%), pneumonia 3 cases(4.9%), subcutaneous emphsema 1 case (1.6%). The most common finding was unilateral hyperlucent lung ( 52.4%), regardless of time interval between foreign body aspiration to hospitalization. 3. Pneumonia and mixed patternwere increased with long time interval between the inhalation of foreign body and admission to the hospital. 4. Afollow-up chest film should be performed, even if there were no abnormal findings on the initial film.