Isolated right heart failure after cardiac surgery is uncommon and the prognosis remains poor. Additionally, managements for these patients are difficult. Profound postcardiotomy right heart failure developed in a 45-year-old woman after aortic root replacement for critical aortic stenosis with small aortic root. Although maximum medical therapy, intraaortic balloon counterpulsation and extracorporeal membrane oxygenator were attempted, severe right heart failure remained. Finally, an implantable right ventricular assist device (RVAD) was utilized because an immediate myocardial recovery was unlikely. The patient was discharged from the hospital at 17 days after the RVAD implantation. After 79 days of support, right ventricular function had recovered, the fully rehabilitated patient was successfully weaned from the RVAD, and the RVAD was explanted. The patient has no recurrence of heart failure 668 days after RVAD explantation.