PURPOSE: To evaluate the plain chest radiographic findings of smoke inhalation. MATERIALS AND METHODS:Our study included 72 burn patients who had suffered smoke inhalation. On admis-sion,all underwent serial portable chest AP radiography. We retrospectively reviewed the plain chest radi-ographs taken between admission and pootburn day five, evaluating the pattern, distribution, and time onset of direct injury to the respiratory system by smoke inhalation. The lesions were also assessed for change. RESULTS: In 16 of 72 patients (22%), abnormal findings of direct injury to the respiratory system by smoke in-halation were revealed by the radiographs. Abnormal findings were 15 pulmonary lesions and one subglottic tracheal narrowing. Findings of pulmonary lesions were multiple small patchy consolidations (10/15), peri-bronchial cuffing (8/15), and perivascular fuzziness (6/15). Patterns of pulmonary lesions were mixed alveolar and interstitial lesion (n=9), interstitial lesion (n=5), and alveolar lesion (n=1). No interlobular septal thicken-ing was observed. Pulmonary edema was distributed predominantly in the upper lung zone and perihilar re-gion, with asymmetricity. Its time of onset was within 24 hours in 13 cases, 24 -48 hours in two cases, and 48 -72 hours in one. Five of 16 patients progressed to ARDS. CONCLUSION: Chest radiographs showed that pulmonary lesions caused by inhalation injury were due to pul-monary edema, which the pattern of which was commonly mixed alveolar and interstitial.