An eight year old boy presented with multiple residual intracardiac shunts and considerable persisting haemolytic anaemia five years after the repair of a single perimembranous ventricular septal defect. Preoperative transthoracic colour flow mapping showed an "acquired" left ventricular right atrial shunt and three small residual ventricular septal defects around the patch. These had been poorly visualised by both angiography and conventional cross sectional echocardiography and pulsed and continuous wave Doppler. Clearly, to stop the haemolysis effectively, closure of all residual intracardiac shunts was required. Intraoperative pre-bypass colour flow mapping was successfully used to confirm the precise number and nature of the defects and more importantly studies after bypass were used to confirm immediate closure of all defects.