Right ventricular dysfunction is not uncommon in adults with congenital heart disease. In congenital heart disease, unlike acquired heart disease, the right ventricle is not always the subpulmonary ventricle: it may support the systemic circulation as it does in patients with transposition complexes. The result is chronic right ventricular pressure overload. In contrast, pulmonary valve regurgitation -a frequent problem after surgical repair of the tetralogy of Fallot- imposes a volume overload on the right ventricle. Over time, both conditions may lead to right ventricular dysfunction and often this becomes a major clinical concern. Clearly, a thorough understanding of right ventricular anatomy and physiology is a necessity for those caring for patients with congenital heart disease. This article provides an overview of right ventricular morphology and the adverse effects of right ventricular dysfunction in adults with congenital heart disease.