A case of malignant schwannoma occurring in an 11-year-old boy is described. To our knowledge, this is the third case of malignant juxta-adrenal schwannoma reported in the literature. It was misdiagnosed at the onset of the disease as a post-traumatic renal hematoma. Angiography revealed that the tumor derived its blood supply from collateral vessels of the aorta, splenic, and left gastric arteries. An analysis of the diagnosis, clinical course, and prognostic factors of this rare tumor is performed.