The present study evaluates the feasibility and effectiveness of tandem high-dose chemotherapy and autologous stem cell transplantation (HDCT/autoSCT) in very young children with anaplastic ependymoma. We aimed both to improve survival and to avoid unacceptable late adverse effects of radiation therapy (RT) by avoiding or deferring RT until 3 years of age. Five consecutive patients younger than 3 years of age with anaplastic ependymoma were enrolled from April 2006 to November 2008. Tandem HDCT/autoSCT was given following six cycles of induction chemotherapy. RT was either not given or deferred until 3 years of age if the patient was in complete response after tandem HDCT/autoSCT. Median age at diagnosis was 16 (range 12-28) months. Four patients had significant residual tumor (>1.5 cm(2)) after initial surgery, and three had leptomeningeal seeding. Toxicities during induction chemotherapy and tandem HDCT/autoSCT were manageable. No tumor progressed during induction chemotherapy and tandem HDCT/autoSCT, and RT was thus avoided or deferred until 3 years of age in all patients. All patients are alive at median follow-up of 45 (range 31-62) months from diagnosis, although tumor progressed in one patient. No significant endocrine dysfunction occurred except for hypothyroidism in one patient. Cognitive function was also acceptable in all patients but one who had significant neurologic injury during surgery. Our results indicate that treatment with tandem HDCT/autoSCT is feasible in very young children with anaplastic ependymoma and may improve the survival of patients with acceptable long-term toxicity.