Imaging morphology and function of the right heart is of paramount importance in patients with adult congenital heart disease, since right ventricular dysfunction is associated with adverse cardiac events. Cardiac MRI has been shown to be a powerful tool for the non-invasive precise assessment of right ventricular and valvular dysfunction. Differential diagnoses of congenital heart disease characterised by, or combined with, right heart dilatation are diverse and necessitate a systematic approach.