This study aimed to investigate the prohepcidin levels in premature newborns with oxygen radical diseases such as bronchopulmonary dysplasia, retinopathy of prematurity and necrotizing enterocolitis and to compare these levels with those of healthy premature newborns. Eighty premature infants (25-34 weeks gestational age) were enrolled. The patient group was composed of 38 premature babies with oxygen radical diseases, and the control group consisted of 42 healthy premature newborns. Complete blood count, serum iron and ferritin concentrations, iron-binding capacity (IBC), transferrin and prohepcidin levels were measured. The mean ferritin and prohepcidin levels were higher in the patient group than in the control group (p = 0.038 and p = 0.022, respectively). No significant correlations were found between serum prohepcidin levels and iron parameters. We believe that this finding will contribute to a greater understanding of the etiopathogenesis of oxygen radical diseases. There is a need for future studies to explore the link between underlying inflammatory mechanisms and hepcidin in oxygen radical diseases.