Chronic oxygen dependence is associated with immaturity, male sex and low birthweight, but amongst that high risk group further criteria are necessary to predict those most at risk. We previously developed a chest radiograph scoring system which, when used at 1 month of age, proved useful in predicting chronic oxygen dependency at 36 weeks post-conceptional age (PCA). We have now assessed whether the scoring system, if applied at 24 h of age, added predictive value to readily available demographic and ventilatory data. 50 infants, birthweight less than 1200 g and ventilated from birth, were examined. They had a median gestational age of 27 weeks (range 23-34), birthweight of 886 g (range 470-1172) and chest radiograph score of 7 (range 2-13). Univariate analysis revealed that oxygen dependency at 28 days and 36 weeks PCA was significantly associated with low gestational age, male sex and high ventilatory requirements, in addition to a high chest radiograph score. Stepwise regression analysis, however, demonstrated that a high chest radiograph score predicted oxygen dependence at 28 days, independent of immaturity, low birthweight, male sex and high ventilatory requirements. A chest radiograph score of more than 5 rendered an infant four times more likely to be oxygen dependent at 28 days than those with lower scores. We conclude the chest radiograph appearance at 24 h of age could be used as a criterion to institute interventional strategies aimed at reducing chronic oxygen dependence.