Purpose: To assess levels of distress, the marital relationship, and styles of coping of parents of children with congenital heart disease, to evaluate any change in these parameters following elective cardiac surgery for their child, and to compare these parents with parents of children undergoing another form of hospital treatment, and with parents of healthy children. Design: A prospective study in which parents were assessed the day before the surgical procedure being undergone by their child, and 12 months afterwards. Participants: We assessed three groups of parents of 75 children, aged from birth to 16.9 years. The first was a group whose children were undergoing surgery because of congenital heart disease, the second was a group whose children were undergoing transplantation of bone marrow, and the third was a group whose children were healthy. Measures used for assessment included the General Health Questionnaire, the Dyadic adjustment scale, and the Utrecht coping list. Results: Parents in both groups of children undergoing surgery had significantly higher rates of distress prior to the surgical procedures than did the parents of the healthy children, but within those whose children were undergoing cardiac surgery, there were no differences between parents of children with cyanotic and acyanotic lesions. Following treatment, there was a significant reduction in the levels of distress in both groups whose children had undergone surgery. There were few differences between any of the groups on the other parameters, and the evaluated indexes showed stability over time. Conclusion: Despite elevated levels of psychological distress prior to surgical procedures, which had fallen after one year, the stability of other parameters of parental functioning over time suggests that the surgical interventions are of less significance than either factors attributable to the presence of chronic illness, or the individual characteristics of the parents.