The birth and hospitalization of a preterm infant have powerful effects on the emerging parent-infant relationship. Characteristics of parents, infant factors, and factors in the hospital and Neonatal Intensive Care Unit (NICU) environments--in addition to the circumstances surrounding preterm birth--may disrupt parent-infant relationships. Parents make extraordinary efforts to maintain relationships with their hospitalized premature babies; fathers of preterm infants may be more involved in their care than fathers of full-term babies. The task-oriented NICU environment sometimes overlooks relationship development. Infant-family professionals can reduce the negative effects of relationship disruptions and promote the mental health of preterm babies and their families through psychoeducational interventions with families, mental health services in the NICU, staff training to support the parent-infant relationship, emotional support for NICU staff, and developmentally supportive and family-centered practices.