Wilms' tumor represents one of the most frequent neoplastic disease of childhood: its prevalence is about 5-8 cases per million children aged less than 15 years, and its frequency ranks fourth among childhood solid tumors. Very marked improvement in the treatment of this lesion has occurred since 1942 with a 15% survival rate was reported. The modern approach to Wilms' tumor and its treatment based on the combination of surgery with chemo- and radiotherapy raised the survival rate to 80-95%, as shown by several cooperative studies performed in the United States and Europe. The nosographic, diagnostic and therapeutic aspects of the disease are reviewed and illustrated on the basis of the diagnostic imaging and anatomical features of cases treated by the authors.