Within a family perspective on quality of life (QL) with congenital heart disease, the study investigates parental QL, and patients' health-related QL as reported by themselves and by their parents. We examined the hypotheses that parental QL moderates the parental proxy reports. Sixty-nine patients (7-20 years, 61% male) and their caregivers participated in a computer-assisted QL-assessment. Children's self-rated and proxy-rated QL correlated moderately, with the highest intra-class correlation on the subscale psychological well-being/functioning (r = 0.61; p < 0.001), less convergence in physical well-being/functioning (r = 0.49; p < 0.001) and absent correlation in the evaluation of intra-family relationships. Parental QL was correlated both with the children's self-rated QL (r = 0.42; p < 0.05) and children's parent-rated QL (r = 0.60; p < 0.001). Support for the moderator hypotheses is indicated by the results of regression analyses demonstrating a significant interaction effect of parental QL and patients' self-reported QL in predicting parental proxy reports on their children's QL. Post-hoc tests reveal that parents with low own QL agree significantly more with their children than parents with high QL. Parent-child agreement on the children's QL is limited and reflects complementary subjective viewpoints. Psychosocial interventions should be family-focused and provide support for patients' and their caregivers' QL.