To evaluate whether extremely preterm infants regulate iron status via hepcidin. In this retrospective analysis of infants from the Preterm Epo Neuroprotection (PENUT) Trial, urine hepcidin (Uhep) normalized to creatinine (Uhep/UCr) was evaluated among infants randomized to erythropoietin (Epo) or placebo. The correlation (r) between Uhep/UCr and serum markers of iron status (ferritin and zinc protoporphyrin-to-heme ratio [ZnPP/H]) and iron dose was assessed. A total of 243 urine samples from 76 infants born at 24-276/7weeks gestation were analyzed. The median Uhep/UCr concentration was 0.3, 1.3, 0.4, and 0.1ng/mg at baseline, 2weeks, 4weeks, and 12weeks, respectively, in placebo-treated infants. The median Uhep/UCr value in Epo-treated infants were not significantly different, with the exception of the value at the 2-week time point (median Uhep/UCr, 0.1ng/mg; P<.001). A significant association was seen between Uhep/UCr and ferritin at 2weeks (r=0.63; P<.001) and at 4weeks (r=0.41; P=.01) and between Uhep/UCr and ZnPP/H at 2weeks (r=-0.49; P=.002). Uhep/UCr values correlate with serum iron markers. Uhep/UCr values vary over time and are affected by treatment with Epo, suggesting that extremely preterm neonates can regulate hepcidin and therefore their iron status. Uhep is suppressed in extremely preterm neonates, particularly those treated with Epo.