Pediatric cancer is relatively rare compared to cancer in adults. Most pediatric neoplasms affect the hemopoietic and central nervous systems. Of the solid extracranial tumors, renal and genitourinary lesions are among the most frequent pediatric neoplasms. Wilms tumors (nephroblastomas) and their variants predominate. Others are less frequent, and their rarity leads to significant diagnostic challenges. This review presents the most important points for diagnosis using histopathological, immunophenotypical, and molecular novel information on the most important renal and genitourinary pediatric neoplasms.