At 31 weeks gestation, a hydropic male fetus died in utero with metastatic disease from a renal clear cell sarcoma. The tumor had metastasized to para-aortic and mediastinal lymph nodes, lung, pleura, and liver, leading to superior vena cava obstruction and pulmonary hypoplasia. The pathologic findings and cytogenetic analysis of the fetus and tumor are presented. In addition, review of the literature reveals six other cases aged <6 months of age, including two extrarenal cases.