We present a new case of leiomyosarcoma, a very rare clinical entity, arising from the renal pelvis. The primary diagnosis, based on asymptomatic gross hematuria and imaging findings, was tumor of the left kidney. After a left radical nephro-ureterectomy, histology confirmed a leiomyosarcoma of the renal pelvis. No adjuvant treatment was provided and the patient remains healthy 3 years after surgery.