To evaluate the clinical utility of urinary β-2-microglobulin (B2M) at birth, an alternative to proinflammatory cytokines, as an indicative marker of fetal inflammatory response and subsequent higher risk of bronchopulmonary dysplasia (BPD) in premature infants.The relationship between urinary B2M at birth and the occurrence of BPD was examined in 96 premature infants with a description of perinatal backgrounds. Constructing a receiver-operating characteristic curve to determine the cutoff value of urinary B2M at birth for the development of BPD, a multivariate logistic regression analysis was performed to evaluate whether elevated urinary B2M at birth can be used as a predictor of BPD.BPD was diagnosed in 34% (33/96) of the infants. Neonates with BPD had a significantly higher occurrence rate of chorioamnionitis and greater levels of median urinary B2M at birth than did those without BPD. The selected cutoff value of urinary B2M at birth correlated with the development of BPD, even after adjusting for gestational age and other confounding factors.Elevated urinary B2M levels at birth can be used as an alternative marker of fetal inflammatory response and subsequent higher risk of BPD in premature infants.