We describe a 2-year-old girl with tetralogy of Fallot and pulmonary atresia, palliated as a neonate with a right modified Blalock Taussig shunt, who developed severe cyanosis following total correction in the absence of corresponding evidence of parenchymal lung disease on the chest X-ray. Selective pulmonary angiography showed new intrapulmonary shunting involving only the right middle and lower lobes only. The cyanosis resolved rapidly subsequent to inhalation of nitric oxide. To our knowledge, this is the first documented case of rapid onset of localised intrapulmonary right-to-left shunting, involving only two lung lobes, following biventricular repair for complex congenital heart disease.