BACKGROUND: The Pediatric Oncology Group performed a pilot study to assess the feasibility of tandem high dose chemotherapy (HDC) with stem cell rescue (HDC/SCR). We report here the results of this single arm trial of induction chemotherapy, local control measures (surgery and local radiation), and tandem HDC/SCR. PROCEDURE: Patients with high risk neuroblastoma (NBL) underwent five cycles of induction chemotherapy and resection of primary tumors. Peripheral blood stem cells (PBSC) were collected after Course 3 without exvivo manipulation. Myeloablative chemotherapy was performed in rapid sequence after induction chemotherapy and surgery. The ability of patients to complete both cycles of HDC/SCR was a primary endpoint. Transplant-related toxicity, progression-free survival (PFS) and overall survival (OS) were recorded. RESULTS: A total of 33 patients were enrolled. Twenty-two patients completed at least one HDC/SCR procedure and 17 patients completed both. Only one patient had insufficient stem cells collected for both transplants. There was one transplant-related death; engraftment was rapid and toxicity was as expected. The PFS of the 33 patients treated on this study is 24.2% +/- 7.5% and OS is 36.4% +/- 8.4% at 5 years. For patients who received at least one transplant PFS is 36.4% +/- 11.0% and OS is 45.5% +/- 11.2% at 5 years. CONCLUSIONS: The treatment of high risk NBL with tandem HDC/SCR is feasible in terms of transplant-related mortality and the ability to collect adequate PBSC for two transplants. The outcomes from this intensified treatment have been used to design a Children's Oncology Group Phase III study testing the efficacy of tandem HDC/SCR. Pediatr Blood Cancer 2012; 59: 902-907. (c) 2012 Wiley Periodicals, Inc.