Acute right ventricular failure after cardiac surgery occurring in the first postoperative hours is associated with a bad prognosis. We have used a centrifugal pump either for left, right or biventricular assistance. However, the use of this device for pure right ventricular assistance is rare. We report a 30 year-old female undergoing a mitral valve replacement and a 42 year-old male undergoing a cardiac transplantation, who had a successful right ventricular assistance using a centrifugal pump, due to a failing right ventricle, as the result of insufficient myocardial protection and severe pulmonary hypertension. These two cases illustrate the value of the mechanical ventricular assist device for the treatment of right heart failure (Rev Méd Chile 2008; 136: 359-66). (