We present the case of a two and a half year old child with idiopatic dilated cardiomyopathy and end-stage congestive heart failure (NYHA III-IV) who underwent "partial ventriculectomy". The operation was performed under normothermic cardiopulmorary bypass and normothermic oxygenated blood cardioplegia and consisted of removal of a large wedge of muscle from the lateral wall of the left ventricle beginning at the apex and extending between the papillary muscles, ending proximal to the mitral annulus. Pre-operative the left ventricular ejection fraction (EF) was 13% by echocardiography and 20% by radionuclide ventriculography. Postoperative avaliation showed improvement of EF to 50% and 30%, respectively. The child was in functional class I (NYHA) on discharge from hospital (16th postoperative day).