OBEJCTIVE: To prospectively assess parental health-related quality of life (HRQoL) and its predictors after child open heart surgery. STUDY DESIGN: Mothers (n = 135) and fathers (n = 97) of 138 children were assessed at discharge from hospital and 6 months after open heart surgery of their child. Parental HRQoL was compared with population norms. Medical, demographic, and psychosocial predictors of HRQoL were examined. RESULTS: In both parents, several domains of HRQoL were decreased at their child's hospital discharge with mothers showing lower HRQoL than fathers. Mental domains were more affected than physical domains. At 6 months, parental HRQoL was within or above population norms. At discharge, symptoms of post-traumatic stress and at 6 months a high impact of the child's disease on family life were associated with low mental HRQoL in both parents. In mothers, lower socioeconomic status and foreign nationality were also associated with a higher risk for low mental HRQoL at discharge. CONCLUSIONS: Parents' mental HRQoL is low in the immediate period after their child's open heart surgery but normalizes after 6 months. However, parents in whom the child's disease has a high impact on their family life are at increased risk for persistent low mental HRQoL.