88 children with primary renal tumours (85 with nephroblastoma and 3 with renal cell carcinoma) were treated between 1973 and 1990 in the paediatric urology department of Institute "Pirogov" and the paediatric haematological oncology department in Sofia. Combined therapy includes early surgery (nephrectomy + lymphadenectomy) and combination chemotherapy (Dactinomycin, Vincristine + Adriamycin, Endoxan). Stage II (with lymph node in involvement), III and IV disease was treated by radiotherapy. Chemotherapy and preoperative radiotherapy were administered in the case of very large tumours. In this series of 88 children, 64 (72.2%) are alive and 21 (23.8%) have died, while no information was available for 3 cases (3.5%). Survival was related to clinical stage, histological type and the child's age. One of the 2 cases with bilateral tumours survived for more than 2 years after the operation and combined therapy. One girl with liver and spleen metastases survived in remission for 11 years after the operation. Two children with pulmonary metastases, discovered one year after surgery for the primary tumour survived in remission for 4 and 14 years, respectively. The authors discuss the good results obtained with early combined therapy in this type of tumour.