Four cases of bilateral nephroblastoma out of a total number of 99 cases have been observed during a period of 18 years at the INSE of Tunis (4%). The frequency of associated anomalies, the familial incidence, the young age of the patients are underlined. The main therapeutic modalities are discussed. Based on the most recent studies published in the literature, the prognosis of bilateral nephroblastoma has been improved in recent years with a possibility of survival at 2 years exceeding two thirds of the cases.