Each year advances are made in the clinical evaluation and treatment of genitourinary tumors in children. Understanding of cellular, molecular, and genetic processes in tumorigenesis is evolving rapidly. In addition, information is accumulating about the long-term outcome and complications associated with treatment modalities. This article reviews the 2001 literature on pediatric Wilms tumor, other renal tumors, rhabdomyosarcoma of the pelvis, paratesticular rhabdomyosarcoma, and testicular tumors. The emphasis in molecular biology is to identify molecular or genetic markers that predict outcome. The National Wilms' Tumor Study Group reported on the complications of surgery and the decreased complication rate when these procedures are performed by pediatric surgical specialists. Long-term complications of treatment are also discussed, including short stature and leukemia. The Intergroup Rhabdomyosarcoma Study Group reported on the results of treatment for nonmetastatic disease and the goals of the upcoming Study V, reduction of chemotherapy and radiotherapy. They also presented data from Study IV and discussed the findings on improved prognosis.