Objectives. Necrotizing enterocolitis (NEC) is a significant complication for the premature infant. However, subsequent neurodevelopmental and growth outcomes of extremely low birth weight (ELBW) infants with NEC have not been well described. We hypothesized that ELBW infants with surgically managed (SurgNEC) are at greater risk for poor neurodevelopmental and growth outcomes than infants with medically managed NEC (MedNEC) compared with infants without a history of NEC (NoNEC). The objective of this study was to compare growth, neurologic, and cognitive outcomes among ELBW survivors of Surg NEC and MedNEC with NoNEC at 18 to 22 months’corrected age. Methods. Multicenter, retrospective analysis was conducted of infants who were born between January 1, 1995, and December 31, 1998, and had a birth weight < 1000 g in the National Institute of Child Health and Human Development Neonatal Research Network Registry. Neurodevelopment and growth were assessed at 18 to 22 months’postmenstrual age. χ2, t test, and logistic regression analyses were used. Results. A total of 2948 infants were evaluated at 18 to 22 months, 124 of whom were SurgNEC and 121 of whom were MedNEC. Compared with NoNEC, both SurgNEC and MedNEC infants were of lower birth weight and had a greater incidence of late sepsis; SurgNEC but not MedNEC infants were more likely to have received a diagnosis of cystic periventricular leukomalacia and bronchopulmonary dysplasia and been treated with postnatal steroids. Weight, length, and head circumference < 10 percentile at 18 to 22 months were significantly more likely among Surg NEC but not MedNEC compared with NoNEC infants. After correction for anthropometric measures at birth and adjusted age at follow-up, all growth parameters at 18 to 22 months for Surg NEC but not Med-NEC infants were significantly less than for NoNEC infants. Surg NEC but not Med NEC was a significant independent risk factor for Mental Developmental Index < 70 (odds ratio [OR]: 1.61; 95%confidence interval [CI]: 1.05-2.50), Psychomotor Developmental Index < 70 (OR: 1.95; 95%CI: 1.25-3.04), and neurodevelopmental impairment (OR: 1.78; 95%CI: 1.17-2.73) compared with NoNEC. Conclusions. Among ELBW infants, SurgNEC is associated with significant growth delay and adverse neurodevelopmental outcomes at 18 to 22 months’corrected age compared with NoNEC.MedNEC does not seem to confer additional risk. Surg NEC is likely to be associated with greater severity of disease. Objectives. Necrotizing enterocolitis (NEC) is a significant complication for the premature infant. However, subsequent neurodevelopmental and growth outcomes of extremely low birth weight (ELBW) infants with NEC have not been well described. We hypothesized that the ELBW infants with surgically managed (SurgNEC ) are at greater risk for poor neurodevelopmental and growth outcomes than infants with medically managed NEC (MedNEC) compared with infants without a history of NEC (NoNEC). The objective of this study was to compare growth, neurologic, and cognitive outcomes among ELBW survivors of Surg NEC and MedNEC with NoNEC at 18 to 22 months’corrected age. Methods. Multicenter, retrospective analysis was conducted of infants who were born between January 1, 1995, and December 31, 1998, and had a birth weight <1000 g in the National Institute of Child Health and Human Development Neonatal Research Network Registry. Neurodevelopment and growth were assessed at 18 to 22 months’postmenstrual ag Results. A total of 2948 infants were evaluated at 18 to 22 months, 124 of whom were SurgNEC and 121 of whom were at MedNEC. Compared with NoNEC, both SurgNEC and MedNEC infants were of lower birth weight and had a greater incidence of late sepsis; SurgNEC but not MedNEC infants were more likely to have received a diagnosis of cystic periventricular leukomalacia and bronchopulmonary dysplasia and been treated with postnatal steroids. Weight, length, and head circumference <10 percentile at 18 to 22 months were significantly more likely among Surg NEC but not MedNEC compared with NoNEC infants. After correction for anthropometric measures at birth and adjusted age at follow-up, all growth parameters at 18 to 22 months for Surg NEC but not Med -NEC infants were significantly less than for NoNEC infants. Surg NEC but not Med NEC was a significant independent risk factor for Mental Developmental Index <70 (odds ratio [OR]: 1.61; 95% confidence interval [CI]: 1.05-2.50), Psychomotor Developmental Index <70 (OR: 1.95; 95% CI: 1.25-3.04), and neurodevelopmental impairment (OR: 1.78; 95% CI: 1.17-2.73) compared with NoNEC. Conclusions. Among ELBW infants, SurgNEC is associated with significant growth delay and adverse neurodevelopmental outcomes at 18 to 22 months’corrected age compared with NoNEC. MedNEC does not seem to confer additional risk. Surg NEC is likely to be associated with greater severity of disease .