Heart failure is characterised by a triad comprising cardiac abnormality, exercise limitation and neurohormonal activation. The 2% of the adult population who suffer with heart failure are known to derive both symptomatic and prognostic benefit from exercise and pharmacologic neurohormonal antagonism. The existence of heart failure has traditionally been considered in the context of ischaemic, hypertensive, valvular and myopathic disease but in this article we develop the argument that patients with congenital heart disease also manifest all the pathophysiological criteria that constitute the chronic heart failure syndrome. We discuss the inherent limitations to a purely anatomical approach to congenital heart disease, bring attention to the large and rapidly growing population of adults with this condition and conclude by calling for a therapeutic approach to congenital heart disease that is based on the heart failure paradigm.