The Japanese organ transplant law was revised in July 2010 in order to enable children aged <15 years to donate organs. However, the waiting time for orthotopic heart transplantation (HTx) is as long as 636 days in children due to a shortage of organ donors. Ventricular assist devices (VADs) have been widely used as a bridge to transplantation in Western countries, whereas experience with VADs is limited in Japan due to a lack of device availability for small children. This study aimed to clarify the clinical profiles and outcomes of children with advanced heart failure in Japan and to investigate the importance of mechanical circulatory support (MCS), VADs, and extracorporeal membrane oxygenation (ECMO) in children. A retrospective chart review of patients with advanced heart failure who were eligible for HTx between January 2006 and May 2015 was performed at the Department of Pediatric Cardiology, Tokyo Woman’s Medical University, Japan. Patients were divided into two groups based on need for MCS. Clinical data pre- and post-revision of the Japanese organ transplant law were compared. Preoperative clinical conditions were evaluated based on Interagency Registry for Mechanically Circulatory Support (INTERMACS) profiles. Twenty-two patients were included in the study, 12 of whom required MCS. VADs were implanted in nine patients and ECMO was needed in seven patients. Of the MCS group, 5 deaths occurred in patients with a preoperative INTERMACS profile-1. High total bilirubin was found to be associated with mortality by multivariate logistic regression analysis (OR 7.8, p = 0.02). Wait list mortality was 32 % and no difference in clinical profiles pre- and post-revision of the Japanese organ transplant law was observed. Approximately 55 % of pediatric patients with advanced heart failure required MCS support. Preoperative conditions such as INTERMACS profile-1 and high total bilirubin were associated with poor outcomes. The Japanese organ transplant law revision had no significant influence on patient profiles or outcomes.