Nephroblastomas are the most commonly occurring renal neoplasms in childhood and are treated almost exclusively in clinical trials. An important factor for further therapeutic management is the pathological evaluation of the nephrectomy specimen. Tumor stage and risk group classification are the most crucial parameters. An independent assessment of the tumor by a reference pathology center is an essential standard procedure. Although many molecular genetic discoveries have been made in nephroblastomas over recent years, molecular parameters do not (yet) play a role in treatment stratification.