Background: Ruptured renal neoplasms can be a catastrophic clinical presentation. Angiomyolipoma is the commonest renal tumor which presents in this fashion. Renal sarcomas are rare renal neoplasms. Renal leiomyosarcomas are the most common histological subtype of renal sarcomas, accounting for approximately 50-60% of the reported cases. These tumors are usually peripherally located and appear to arise from either the renal capsule or smooth muscle tissue in the renal pelvic wall. Case presentation: A 70 years old male, with hypertension and ischemic disease, developed acute left flank pain. The general physician evaluated this using ultrasound, which showed a solid left renal mass. Two weeks later, he presented in the emergency room in a state of shock with a palpable flank mass. CT scan of the abdomen showed a large heterogeneous mass lesion in the left perinephric space with minimal post contrast enhancement. Peroperatively, large retroperitoneal hematoma was found within Gerota's fascia along with spleen plastered to the upper limit of hematoma. Nephrectomy and splenectomy were performed. Postoperative course was uneventful and patient was discharged on the 10th post-operative day. Histopathological evaluation of the specimen showed high-grade leiomyosarcoma Conclusions: Spontaneous rupture of renal neoplasm is a rare clinical presentation. Angiomyolipoma is the commonest cause of spontaneous rupture of the kidney. Presentation of a leimyosarcoma as a ruptured renal neoplasm has not been previously reported in the English literature.