Renal sarcoma represents 1-3% of all renal malignant tumours. Primary rhabdomyosarcoma of the kidney is a rare and highly aggressive tumor in the adult population. Here, we report the case of a 50-year-old woman with a large rhabdomyosarcoma of the left kidney and associated adrenal cortical adenoma. Rhabdomyo sarcoma is a very rare tumor in adults but it needs to be considered in the differential diagnosis among undifferentiated malignant tumors.