Seven children with neuroblastoma who had relapsed on or after conventional therapy (3 originally stage IV, 3 stage III, 1 stage II) were entered on a study of "massive therapy" with purged autologous bone marrow rescue. In 5 patients attempts were made to reinduce remission with alternative chemotherapy, and a partial or complete response was achieved in 3. The massive therapy regimen comprised melphalan, vincristine, and total-body irradiation. Of 6 patients with measurable disease, all showed objective response to high-dose therapy (5 partial, 1 complete remission), but the median duration of remission was only 5 months (range 1/2 to 10). One patient remains disease-free at 18 months post graft. This patient was the only one treated in second complete remission. These data confirm the high response rate achieved by high-dose melphalan, total-body irradiation regimens, but it appears unlikely that a single high-dose chemoradiotherapy procedure will cure patients after relapse, particularly if they are unresponsive to conventional salvage regimens. Such protocols may, however, have a role as consolidation in first remission. The use of double-autograft procedures is an alternative that warrants further investigation in patients with relapsed neuroblastoma.