Increasing treatment intensity has improved outcomes for children with neuroblastoma. We performed a pilot study in the Children's Oncology Group to assess the feasibility and toxicity of a tandem myeloablative regimen without TBI supported by autologous CD34-selected peripheral blood stem cells. Forty-one patients with high-risk neuroblastoma were enrolled; eight patients did not receive any myeloablative consolidation procedure and seven received only one. Two patients out of 41 (4.9%) experienced transplant-related mortality. CD34 selection was discontinued after subjects were enrolled due to serious viral illness. From the time of study enrollment, the overall 3-year EFS and OS were 44.8+/-9.6% and 59.2+/-9.2% (N=41). These results demonstrate that tandem transplantation in the cooperative group setting is feasible and support a randomized comparison of single vs tandem myeloablative consolidation with PBSC support for high-risk neuroblastoma.