Nephroblastoma is one of the frequent tumours in children. It is the tumour that has most benefited from advances in chemotherapy made during the last twenty years, a period in which its cure rate has increased from 50 to 90%. This tumour is easy to diagnose by radiology and ultrasonography. Its histological features are now well known, and diagnostic problems have become rare. What predominates at present is research on the link which exists between the development of these tumours and certain congenital malformations on the one hand, and certain chromosomal anomalies on the other hand. Deletion of chromosome 11 short-arm is the most common of these anomalies. Nephroblastoma might be one of those tumours which develop due to derepression of cell proliferation. Treatment rests on nephrectomy and chemotherapy which nowadays consists of numerous and effective drugs. Radiotherapy is still used but as little as possible because of the sequelae it creates. Treatment has much benefited from preoperative chemotherapy which improves the results of the latter.