Spontaneous retroperitoneal hemorrhage from the kidney was first described in 1700 by Bonet. Wunderlich gave his name to this rare syndrome in 1856. Up to now, 250 cases are reported. This disease entity is associated with an underlying pathology, which may be a benign tumor such an angiomyolipoma or a malignant tumor such renal cell carcinoma. We report two cases whose presenting features were those of this syndrome. We discuss the radiological characteristics including intravenous pyelography, renal angiography, computerized tomography and magnetic resonance imaging. Preoperative diagnosis is corroborated by surgical exploration and radical nephrectomy. We conclude in recommending computerized tomography as the examination of choice.