Objective: To analyze the value of hematological parameters at different time points in predicting bronchopulmonary dysplasia (BPD) in preterm infants admitted to our hospital.Methods: Premature infants with a gestational age ≤32 weeks admitted to our NICU from January 2020 to December 2023 were retrospectively collected. They were divided into a BPD group (experimental group, 44 cases) and a non-BPD group (control group, 55 cases) based on whether they developed BPD. The changes in blood cells on the day of birth and at 1, 2, 3, and 4 weeks after birth were analyzed, and the receiver operating characteristic (ROC) curve was used to predict BPD.Results: (1) There was no significant difference in white blood cell count between the experimental and control groups at different periods. (2) At 1 week, significant differences were observed in neutrophil count, platelet count (PLT), mean platelet volume (MPV), and red cell distribution width (RDW) between the two groups. At 2 weeks, significant differences were noted in neutrophil count, lymphocyte count, neutrophil-to-lymphocyte ratio (NLR), PLT, and RDW. At 3 weeks, significant differences were found in neutrophil count, lymphocyte count, NLR, eosinophil count, PLT, and RDW. At 4 weeks, significant differences were observed in neutrophil count, NLR, and eosinophil count. Conclusion: Gestational age and an elevated eosinophil count at 4 weeks of birth are independent risk factors for BPD. Hematological parameters have low value in predicting BPD and should be comprehensively judged in combination with clinical data.