To evaluate the psychosocial well-being of 9-18-year-old IVF children. IVF alters fetal programming, with consequences for physical functioning. This also may apply to behavior. Behavior and socioemotional functioning of children born after IVF and spontaneously from parents with former fertility problems were studied, to control for parental factors and investigate the role of IVF on the children's functioning. Child Behavior CheckList (CBCL) and Teacher Report Form (TRF) reports of 139 IVF and 143 control children. VU University Medical Center, Amsterdam. Children's age ranged from 9 to 18 years; mean age 13.60 (+/-2.12) years in IVF and 13.51 (+/-2.11) years in controls. Child's behavior and socioemotional functioning reported by parents (CBCL) and teachers (TRF). The CBCL and TRF mean scores were within the normal range. Scores of IVF parents versus controls were lower on the total problems scale, externalizing scale and syndrome scales thought problems, attention problems, aggressive and rule-breaking behavior. Less IVF children had scores in the borderline/clinical range on these scales. On the TRF, a tendency was found for lower scores on the externalizing scale in IVF children compared with controls. More IVF children scored in the borderline/clinical range on the syndrome scale withdrawn/depressed behavior. Overall, behavior, and socioemotional functioning of 9-18-year-old IVF children is normal. The reduced behavior of externalizing nature reported by the parents, and teacher ratings of more withdrawn/depressed behavior need further study.