Aims: To evaluate the relative effect of cyanosis, surgical interventions and family processes on neuropsychological and behavioural outcomes in 4-year-old survivors of serious congenital heart disease (CHD). Methods: 90 children with a range of cyanotic and acyanotic conditions, who underwent either corrective or palliative surgery, completed a neuropsychological and behavioural evaluation. Families of participants were also profiled by evaluation of maternal mental health, worry, social support, parenting style and family functioning. Results: Compromised neuropsychological outcomes were associated with a combination of cyanotic conditions and open-heart surgery, but this was not exacerbated by having a complex, palliative, status. Both cyanotic and acyanotic conditions were associated with specific sensorimotor delays, regardless of method of the correction. Only children with complex conditions and palliative interventions seemed at risk of poor behavioural outcomes; indeed, children with cyanosis with complete repair showed favourable behavioural outcomes compared with controls. Multivariate analyses highlighted the sometimes greater relevance of family processes (eg parenting style, maternal mental health and worry), rather than disease or surgical factors, in predicting especially behavioural outcomes. Conclusions: The findings (1) suggest a more complex relationship between cyanosis, surgical methods of correction, neuropsychological and behavioural outcomes than previously charted, (2) highlight that family processes may be aetiologically more important than disease and surgical factors, and (3) indicate specific targets for secondary prevention programmes for this at-risk population.