Two implantable left ventricular assist devices(I-LVADs)were approved in Japan in 2011. I-LVADs were used for end-stage heart failure of 20 patients in our institute until March 2012. We examine the clinical course of these 20 patients who were treated with I-LVADs. End points are transplantation, death, or weaning from I-LVADs. Mean hospital days after I-LVAD implantation were 58.1 days, and all 20 patients could discharge from hospital alive. Until September 2012, mean follow up interval was 515 days. Five patients reached heart transplantation, 2 died, weaning from an I-LVAD could be done in 1 patient, and 12 continued to wait for heart transplantation. Survival rate was 100% at 1 month, 95% at 3 months, and 89% at 1 year, respectively. Mean follow up duration after discharge were 457 days, and 16 patients(80%)needed a total of 41 times of readmission in this period. Freedom from readmission was 75% at 1 month, 60% at 3 months, and 25% at 1 year, respectively. In conclusion, prognosis of I-LVAD treatment was good, but many patients needed readmission after I-LVAD implantation and follow up system for I-LVAD treatment should be improved immediately.