Parents’ attitudes and practices may support the children’s reactions to treatments for leukemia and their general adjustment. This study has two aims: to explore parenting depending on child's age and to develop and test a model on how family processes influence the psycho-social development of children with leukemia. Patients were 118 leukemic children and their parents recruited at the Haematology-Oncologic Clinic of the Department of Pediatrics, University of Padua. All parents were Caucasian with a mean age of 37.39 years (SD = 6.03). Children’s mean age was 5.89 years (SD = 4.21). After the signature of the informed consent, the parents were interviewed using the EFI-C from which we derived Parenting dimension and 3 parental perceptions on child’s factors. One year later, the clinical psychologist interviewed again parents using the VABS scales. The analyses revealed the presence of a significant difference in parenting by child’s age: Infants required a higher and more intensive parenting. Child’s coping to medical procedures at the second week after the diagnosis, controlled for parenting effect, impacted upon child’s adaptation one-year post diagnosis. Specific intervention programmes are proposed in order to help children more at risk just after the diagnosis for developmental delays.