PURPOSE: Recent trials of preventive dexamethasone therapy in preterm neonates at high risk of developing bronchopulmonary dysplasia(BPD) have required the objective criteria for prediction of BPD in the early neonatal period. The purpose of this study is to determine whether a chest radiographic scoring system at 7 days of age can be used to predict BPD. MATERIALS AND METHODS: Chest radiographs taken at 7 days and 28 days of age in 59 preterm neonates(gestational age of less than 33 weeks) were scored prospectively according to the consensus of two radiologists. The 7-day radiographs were scored according to a system derived from Yuksel's method : endotracheal tube insertion, degree of lung inflation, lung opacification, interstitial changes and cardiomegaly were measured. The radiographs taken at 28 days were scored according to a modification of Toce's method. The BPD group was defined as consisting of patients who needed oxygen therapy for more than 28 days and showed abnormality on chest radiographs. Scores were analysed to determine whether there were any statistical differences between the BPD and non-BPD groups, whether there was a significant correlation between scores at 7 days and 28 days, and whether there was any relationship between scores at 7 days of age and the development of BPD. We tried to determine which factors, as indicated by the scores at 7 days, significantly contributed to the development of BPD. RESULTS: The mean scores at 7 days of age in the BPD group (n=18) were 4.3±1.5 (2-7), and those in the non-BPD group (n=41) were 2.2±1.2 (0-4). The differences were statistically significant(p<.0001). Significant correlation was found between scores at 7 days and at 28 days of age (r:0.57, p<.0001). Analysis showed that endotracheal tube insertion, cardiomegaly, and degree of interstitial change, as seen on radiographs at 7 days, were factors which significantly contributed to the development of BPD(p<0.05 each). All neonates with a score of 5 or more developedBPD(7/7), while those with a score of less than 2 did not (0/11). CONCLUSION: The chest radiographic scoring system used at 7 days of age can be helpful in predicting the development of BPD. We believe that this system can be used to indicate the need for early preventive steroid therapy.