Objective: To investigate neonatal morbidity and maternal complication rates with delivery body mass index (BMI) 60 or greater. Methods: This retrospective, multicenter cohort study included singleton pregnancies between 23 and 42 weeks of gestation from January 2005 to April 2016. Women with BMI 60 or greater were compared with a random sample of women with BMI 30-59. The primary outcome, composite neonatal morbidity, was defined as 5-minute Apgar score less than 7, hypoglycemia, respiratory distress syndrome, sepsis, hospital stay greater than 5 days, neonatal intensive care unit admission, or neonatal death. Secondary outcomes included maternal labor and delivery characteristics and complication rates. Kruskal-Wallis tests and χ2 or Fisher exact tests were used to compare BMI categories. Multivariable logistic regression was used for adjusted analysis. Results: The study included 338 women, with 39 in the BMI 60 or greater group. An association between obesity and neonatal morbidity was found. Increasing BMI correlated with increasing neonatal morbidity, with the highest rates among those with BMI 60 or greater (BMI 30-39 [17%], 40-49 [19%], 50-59 [22%], 60 or greater [56%]; P<.001). After adjustment for confounders, obese women with BMI less than 60 had at least a 75% reduction in odds of neonatal morbidity compared with women with BMI 60 or greater (BMI 30-39 adjusted odds ratio [OR] 0.22 [0.1-0.5], 40-49 adjusted OR 0.23 [0.1- 0.6], 50-59 adjusted OR 0.25 [0.1-0.6]). Maternal complication rates including labor induction, cesarean delivery, wound complication, postpartum hemorrhage, and hospital stay greater than 5 days were also significantly increased with BMI 60 or greater. Conclusion: A BMI 60 or greater at the time of delivery is significantly associated with increased neonatal morbidity and increased maternal complication rates. In addition, neonatal morbidity and maternal complication rates with BMI 60 or greater were significantly higher when compared with women in any lesser obese BMI cohort between 30 and 59.