PURPOSE: Children and adolescents with malignant astrocytomas recurring after initial treatment have a dismal prognosis, with only rare patients surviving 1-year beyond recurrence. The purpose of this study was to attempt to improve their survival. METHODS: Twenty-seven children and adolescents with malignant astrocytomas [17 glioblastoma multiforme and 10 anaplastic astrocytoma (AA)] following initial tumor progression, received myeloablative chemotherapy followed by autologous marrow rescue with one of three thiotepa and etoposide-based chemotherapy regimens, administered alone (n = 11) or combined with carmustine (n = 5) or carboplatin (n = 11). Time to progression and death following myeloablative chemotherapy for these patients was compared non-randomly with outcome of a contemporaneously treated cohort of similar patients who received only conventional chemotherapy following initial tumor progression. The two cohorts were compared for age, histology, prior therapies, extent of surgical resection at progression, and time from initial diagnosis to progression. RESULTS: Five of 27 children (two with glioblastoma multiforme and three with AA) survive event-free from 8.3 to 13.3 years (median of 11.1 years) following myeloablative chemotherapy. Of 56 children with recurrent malignant astrocytoma who received conventional chemotherapy following initial progression, no patient survives. Differences in distributions of survival were not significant when stratified by surgical debulking (P = 0.39). However, for patients who were surgically debulked, the survival distributions are significantly different (P = 0.017). CONCLUSIONS: Myeloablative chemotherapy with autologous marrow rescue can produce durable remissions in children and young adults with recurrent malignant gliomas, in the setting of minimal residual tumor burden achieved surgically.