Since 1984 a total of 2085 patients with solid tumors have been registered in the European Bone Marrow Transplantation Registry for Solid Tumors (EBMT-STR). The major aim of this registry is to supply data by retrospective analysis for the innovation of prospective, randomized studies. 104 Ewing's sarcoma patients received megatherapy followed by autologous bone marrow transplantation (MGT/ABMT). The 2-year overall survival was 31% in 14 patients with multifocal disease in first complete remission (CR1) and was 37% for 15 patients in second CR (CR2). (6 patients with local disease in CR1 have been excluded.) These results are better than observed under conventional dose chemotherapy. 67 patients were grafted with measurable disease showing a response rate of 72%. The 2-year overall survival was 25% during primary treatments and 33% and 10% for sensitive and resistant relapses, respectively. 201 patients with germ cell tumors received MGT (combinations of platinum derivates, VP16, cyclophosphamide, ifosfamide) followed by ABMT. The overall survival at 5 years was 10% in refractory patients and 58% for 113 responding patients not in CR1 (i.e. first partial remission, CR2 and sensitive relapses). Based on these results and a French randomized trial a prospective, randomized study is underway comparing MGT versus conventional chemotherapy in chemosensitive patients. 219 adults with malignant brain gliomas underwent a program consisting of surgery, MGT (BCNU in the majority)/ABMT and radiotherapy. The overall survival at 3 years was 12%, the median survival was 11 months after ABMT. Life quality after ABMT was good, but no major improvement in terms of prolonged survival was achieved.(ABSTRACT TRUNCATED AT 250 WORDS)