Background: Adults with simple congenital heart defects (CHD) have increased risk of neurodevelopmental challenges including executive dysfunction. It is unknown if the executive dysfunction is universal or if it is driven by dysfunction in specific clinical subscales and how it might affect psychosocial aspects of everyday life. Methods: The self-reported and informant-reported executive function of adults with an average age of 26 +/- 5 (range 18-41) who underwent childhood surgery for atrial septal defects (n = 34) or ventricular septal defects (n = 32) and matched controls (n = 40) were evaluated using the Behavior Rating Inventory of Executive Functions - Adult version (BRIEF-A). Results: The CHD group reported having more executive dysfunction than controls in all BRIEF-A clinical subscales (p < 0.020) and more than their informants reported on their behalf (p < 0.006). The CHD group had received three times more special teaching (44% compared to 16%) and pedagogical psychological counselling (14% compared to none) and had a three times higher occurrence of psychiatric disorders than controls (33% compared to 11%). Lower educational levels and psychiatric disorders were associated with higher BRIEF-A scores (p < 0.03). Conclusions: Adults operated for septal defects in childhood report more challenges with all aspects of the executive functions than controls and more than relatives are aware of.