Leiomyosarcomas originating from renal vein are quite rare malignant tumors since only 30 cases have been reported in the literature. Clinical symptoms which are due to a renal mass along with radiological findings, usually mislead to a preoperative diagnosis of renal cell carcinoma. The correct diagnosis is frequently made on nephrectomy specimens. Low-grade leiomyosarcomas need to be differentiated from leiomyomas. Increased mitotic activity and necrosis are known to be gold standards for differential diagnosis. In this report, we present a case of a 62 year old woman whose tumor in the left kidney diagnosed as low-grade leiomyosarcoma together with a brief review of the literature.