Objective: To investigate whether differences exist in attention deficit hyperactivity disorder (ADHD) and intelligence between children born by cesarean delivery and those born by vaginal delivery. Methods: This retrospective study included singleton children that were born between January 2013 and December 2014. The Chinese version of the Conners’ Parent Rating Scale–Revised (CPRS-48) was required on the probability of psychological and behavioral problems. The China–Wechsler Intelligence Scale for Children (C-WIRS) was used for evaluation of crystallized intelligence and Raven’s Standard Progressive Matrices for evaluation of fluid intelligence. Results: A total of 10,568 valid questionnaires were obtained. CPRS-48 ADHD index and detection rate were higher in cesarean delivery group than those in vaginal delivery group. Cesarean delivery groups had a lower performance intelligence quotient score according to C-WISC. Conclusion Children born by cesarean delivery were more likely to have a risk of ADHD and a lower performance intelligence quotient compared with those born by vaginal delivery.