This study was undertaken to evaluate the association between umbilical cord interleukin- 6 (IL- 6) levels and neonatal morbidity in infants born at less than 32 weeks gestation. Umbilical cord plasma IL- 6 levels and neonatal outcomes were assessed in 309 infants born between 24 weeks and 0 days and 31 weeks and 6 days gestation. Mean IL- 6 levels were higher in spontaneous (n = 193, 355 ± .1822 pg/mL) compared with indicated preterm births (n = 116, 37 ± 223 pg/mL, P <. 0001). Adjusting for gestational age, a progressive relationship was noted between increasing IL- 6 levels and increased risk of neonatal systemic inflammatory response syndrome (SIRS). IL- 6 levels beyond the 90th percentile (≥ 516.6 pg/mL) were also significantly associated with periventricular leukomalacia (PVL; odds ratio 15, 95% CI 2- 149) and necrotizing enterocolitis (NEC; OR 6, 95% CI 1.1- 33). In the multivariate analysis, an IL- 6 level 107.7 pg/mL or greater (determined by receiver operating curve analysis) remained a significant independent risk factor for PVL (OR 30.3, 95% CI 4.5- 203.6). Umbilical cord IL- 6 levels are higher in preterm infants born after spontaneous preterm labor or premature rupture of membranes. Elevated IL6 levels are associated with an increased risk for SIRS, PVL, and NEC in infants born at less than 32 weeks gestation. This study was undertaken to evaluate the association between umbilical cord interleukin-6 (IL-6) levels and neonatal morbidity in infants born less than 32 weeks’ gestation. Umbilical cord plasma IL-6 levels and neonatal outcomes were assessed in 309 infants born Mean IL-6 levels were higher in spontaneous (n = 193, 355 ± .1822 pg / mL) compared with indicated preterm births (n = 116, 37 ± 223 pg / mL, P <. 0001). Adjusting for gestational age, a progressive relationship was noted increasing IL-6 levels and increased risk of neonatal systemic inflammatory response syndrome (SIRS). IL-6 levels beyond the 90th percentile 516.6 pg / mL) were also significantly associated with periventricular leukomalacia (PVL; odds ratio 15, 95% CI 2- 149) and necrotizing enterocolitis (NEC; OR 6, 95% CI 1.1-33). In the multivariate analysis, an IL - 6 level 107.7 pg / mL or greater (determined by receiver operat ing curve analysis) was a significant independent risk factor for PVL (OR 30.3, 95% CI 4.5- 203.6). Umbilical cord IL-6 levels are higher in preterm infants born after spontaneous preterm labor or premature rupture of membranes. Elevated IL6 levels are associated with an increased risk for SIRS, PVL, and NEC in infants born at less than 32 weeks’ gestation.