Inflammatory myofibroblastic tumor (IMT), also known as inflammatory pseudotumor, is an uncommon benign tumor that has been reported in various locations throughout the body, but rarely in the kidney. To our knowledge, only 22 cases of renal IMT have been described in the literature. Renal IMT in children is difficult to differentiate from a malignancy such as Wilms' tumor. We report a case of a 9-year old girl with a left renal mass mimicking malignancy on preoperative diagnostic images, which was pathologically revealed to be an IMT. We review the literature and discuss the pathophysiology and clinical features of this unusual tumor.