PURPOSE: To analyze differences in the radiologic and clinical findings of pulmonary complications between an inhalation and non-inhalation group of major burn patients, and to apply the findings to the specific diagnosis of pulmonary complications. MATERIALS AND METHODS: This study involved 45 major burn patients (18 with inhalation injury, and 27 without) in whom pulmonary complications ensued. Follow-up studies were based on chest radiographs obtained between initial burn day and postburn (PB) 57 (mean, day 27). Types, times of onset, underlying causes, and changes at follow-up study of pulmonary complications between the inhalation and the non-inhalation group were assessed. RESULTS: In the inhalation group, the most frequent complication was air-borne pneumonia (n=7, 39%); others were hydrostatic pulmonary edema (n=5, 28%), ARDS (n=5, 28%), atelectasis (n=5, 28%), inhalation pneumonitis (n=3, 17%), pleural effusion (n=3, 17%), and hematogenous pneumonia (n=1, 6%). In the non-inhalation group, airborne pneumonia (n=8, 30%) was also the most common complication; other were hydrostatic edema (n=6, 22%), ARDS (n=5, 19%), atelectasis (n=5, 19%), pleural effusion (n=5, 19%) and hematogenous pneumonia (n=2, 7%). The average times of onset were as follow: for airborne pneumonia, PB day 13.1 (range, 5-27) in the inhalation group, and PB day 21.7 (10-49) in the non-inhalation group; for hematogenous pneumonia, more than one month, regardless of inhalation; for ARDS, PB day 4.9 (2-15) and PB day 13 (7-20) in the inhalation and non-inhalation group, respectively; and for inhalation pneumonitis, PB day 1.7 (1-3). The most common probable cause of ARDS in the inhalation group was inhalation injury (3/5), and in the noninhalation group, sepsis (4/5). CONCLUSION: In major burn patients, pulnonary complications differed in terms of their onset time and causes between the inhalation group and the non-inhalation group. In such cases, awareness of the presence or absence of inhalation injury and the onset time of pulmonary complications is necessary if complications are to be specifically diagnosed.