Background/aim: It has been suggested that plasma KL-6 increases in premature infants with bronchopulmonary dysplasia (BPD). We aimed to evaluate the predictive values of KL-6 in BPD. Materials and methods: The study was performed in preterm neonates with birthweight ≤1500 g and gestational age ≤32 weeks. Plasma KL-6 levels were measured on postnatal days 1, 7, and 14. Results: BPD was identified in eight of the 28 study infants. On postnatal days 1 and 7, plasma KL-6 levels were similar in infants with BPD [on day 1: 8.9 (7.5-17.8) U/mL and on day 7: 16.8 (10.5-47.7) U/mL] and without BPD [on day 1: 10.8 (9.4-17.2) U/mL and on day 7: 12.9 (5.8-19.3) U/mL] (P = 0.38 and P = 0.13, respectively). On day 14, KL-6 levels were significantly higher in infants with BPD [155.2 (15.3-545.6) U/mL] than they were in infants without BPD [7.9 (7.7-15.6) U/mL] (P = 0.001). The best predictor was KL-6 levels on postnatal day 14 (area under the ROC curve = 0.88; range 0.75-1.0; P = 0.002). At this point, KL-6 level of 59.7 U/mL showed a specificity of 90.0% and negative predictive value of 85.7% for BPD. Conclusion: High plasma KL-6 levels on postnatal day 14 in premature infants may predict the development of BPD.