Wunderlich's syndrome is defined as a clinical manifestation secondary to sudden spontaneous rupture of renal parenchyma in the absence of injury, resulting in hemoretroperitoneum. This syndrome may occur in patients with benign or malignant neoplasm of the kidney, arterial venous fistulae, immunovasculitis and other phlogosis of the kidney. We present 19 cases of acute spontaneous hemoretroperitoneum or Wunderlich's syndrome diagnosed from 1996 to 2009, related to the following conditions: 7 renal carcinomas, 4 angiomyolipomas, 2 adrenal hemorrhages, 1 bleeding polycystic kidney, 2 hemorrhagic renal cysts and three cases of immunovasculitis. Overall, 6 patients were treated with acetylsalicylic acid and 4 with dicumarolics for cardiovascular disease, while 13 patients were suffering from hypertension? In 19 cases there was no mortality and the following treatment was performed: 11 nephrectomy, 4 partial nephrectomy, 2 adrenalectomy, 2 selective embolization of intrarenal branches as single treatment, while in three other cases, the embolization was carried out from a surgical procedure, conservative (partial nephrectomy) in one case, ablative (nephrectomy) in two other cases. The spontaneous hemoretroperitoneum is a rare syndrome associated with acute kidney disease often unknown to the patient and only in selected cases with small hematoma; it is possible to perform arteriography with selective embolization of branches avoiding renal access surgery. So far, it is unknown to which extent anti-platelet and anticoagulant drug treatment contributes to this syndrome but, in our experience, they have increased the morbidity of the clinical condition.