Since January 1980, 120 children affected by Wilms' tumor have been treated at Bambino Ges, mostly with multimodality treatment according to Socit Internationale d'Oncologie Pediatrique (SIOP) protocols, including chemotherapy, surgery and radiotherapy in selected cases. This treatment approach emphasizes the role of preoperative (neoadjuvant) chemotherapy as opposed to the approach favored by the National Wilms' Tumor Study, which is focused on optimizing postoperative chemotherapy after primary surgery. Thus, using SIOP guidelines, staging occurs at the time of surgery, after chemotherapy administration. These differences will constitute the baseline for a comparison between the two experiences. Bilaterality, nephroblastomatosis, partial nephrectomy in unilateral Wilms' tumor and thrombosis of the vena cava are the main topics discussed. For the present study, the analysis was restricted to 98 consecutive cases diagnosed until December 1999, for whom at least 24 mo of follow-up is available. The more recent experience of treating resectable neuroblastoma in cooperative studies dates back to 1979, when the first Italian Cooperative Group Neuroblastoma protocol was introduced. This experience was continued within the frame of the first Localized Neuroblastoma European Study Group protocol (LNESG 94), and will be compared to North American Cooperative Group approaches and outcomes. Preoperative evaluation of surgical risk factors, intraoperative complications and their management, and long-term outcome will be discussed.