This study compared the well-being among mothers of children with congenital heart defects (CHD) with mothers of children without CHD (controls), at pregnancy and at 6 months postpartum. We linked prospective data from the Norwegian Mother and Child Cohort Study (MoBa), conducted by the Norwegian Institute of Public Health, with a nationwide medical CHD registry. In the MoBa cohort of 61,456 mothers, we identified 212 mothers of infants with mild (n=92), moderate (n=50), or severe CHD (n=70). Subjective well-being was operationalized by means of maternal life satisfaction, joy, and anger at the 30thweek of gestation and at 6months postpartum. Subjective well-being in mothers of children with CHD remained unchanged and similar to that of controls on satisfaction with life (P=0.120) and feelings of joy (P=0.065). However, at child age 6months, mothers of infants with severe CHD reported slightly elevated feelings of anger compared with controls (P=0.006). Joy and life satisfaction remained intact among mothers of children with CHD. Yet, elevated feelings of anger in mothers of children with the most severe CHD suggest that they may experience more frustration.