The surgical treatment of malignant renal tumours in children (nephroblastomas) is part of a multimodal therapeutic strategy, defined by the International Society of Paediatric Oncology protocol. Resection of the primary tumour and determination of the post-operative stage determine subsequent treatment. The modalities of the surgical procedure are described together with the particular cases concerning infants under the age of 6 months, extension to the renal vein and inferior vena cava, emergency surgery, bilateral, tumours or tumour in a solitary kidney, lymph node involvement, metastatic nephroblastomas and complications of surgery.