Parents of preterm infants commonly experience separation from their infant or exclusion from their role as primary caregivers during the hospital care of their infant, which may impair parent-infant bonding and parents' psychological well-being. Therefore, we developed the Close Collaboration with Parents™ intervention to improve staff skills in communicating and collaborating with parents in neonatal intensive care units (NICU), to increase parents' presence and participation into infant care, and to improve parent-infant bonding and, thereby, parents' psychological well-being and later child development. The Close Collaboration with Parents™ intervention was developed and carried out at Turku University Hospital. The intervention was based on developmental theories about early parenthood and parent-infant attachment. The training was targeted at both doctors and nurses. The goals of the training included understanding individual behaviors and responses of infants and the uniqueness of families, using receptive listening skills in communication with parents and making decisions collaboratively with them. By increasing the sensitivity of the staff to the individual needs of infants and parents and by increasing staff-parent collaboration in daily care, the intervention supported parents' presence and parents' participation in the care of their infant. The effectiveness of the intervention is being evaluated in a prospective study comparing the post-intervention cohort (n=113) to the baseline cohort (n=232). The outcomes include bonding, long-term psychological well-being of both mothers and fathers and child development up to 5 years of age. The Close Collaboration with Parents™ intervention potentially offers a preventive and salutogenic model to integrate parents and parenting in neonatal hospital care.