The hospitalization of a child for cardiac surgery is known to be a stressful experience for parents. However, little is known about the time course or the relationships between parental stress and the child's actual or perceived recovery. This research aimed to investigate pre- and postoperative parental stress and to examine some of the influencing factors during the postoperative period for children undergoing elective cardiac surgery. Parents of 211 children completed questionnaires and structured interviews preoperatively and on postoperative days 3, 5, 8, and 15. The stress of the parents remained moderate to high throughout their children's hospitalization regardless of the severity of illness. Parents' perceptions of their children's level of illness correlated with an objective measure of postoperative morbidity. There were few differences between mothers' and fathers' stress or their perceptions of their children's illness. Parents in more deprived communities and mothers born outside the UK had higher stress levels. These findings indicate the negative impact of children's surgery and intensive care hospitalization on parents. Better identification of parents at risk for high stress and specific interventions to improve parental support and coping are needed.