To our knowledge intra-abdominal desmoplastic round cell tumor has not previously been described in the pediatric urological literature. This lesion has only recently been recognized as a clinicopathological entity with predilection for adolescent boys. We report on 2 patients who presented with urological symptoms and a large abdominal or pelvic tumor that was biopsied at exploratory laparotomy. Complete surgical excision was impossible in both patients, who subsequently underwent multiagent chemotherapy. Histological and immunohistochemical staining are distinctive in this condition. The tumor is associated with a poor prognosis, despite multidisciplinary, multimodal therapy.