Inflammatory pseudotumor, originally described in the lung, is a relatively rare tumor-like lesion that occurs in various organs and tissues. It is usually well demarcated from the surrounding tissue, however it can be unfortunately resected as a malignant tumor. A few inflammtory pseudotumor in the kidney have been reported in English literature, but there have been no reports in Korea. We report a case with inflammatory pseudotumor of the kidney. A 48 year old woman had an intermittent flank pain on the right side. An ultrasonographic study suggested a renal cell carcinoma and a nephrectomy was done. Grossly, there were two separate masses with a well demarcated yellowish appearance, measuring 2.3 cm and 1.3 cm in diameter, respectively. Histologically, they were composed of smooth muscle actin positive spindle cells and a large number of foamy histiocytes, lymphocytes, and plasma cells in the fibrotic backgound.