Spontaneous rupture of the bladder is a rare event. The clinical presentation shows the signs and symptoms of peritonitis, but the diagnosis is made at the operating table. This event is burdened with a high mortality rate. We present a case report of a 73-year-old man who came to our observation. He was a chronic carrier of urinary catheter, at least 7 times removed traumatically by himself. At the time of admission he showed drastic reduction in urine output, absence of hydronephrosis, normal functioning of the catheter, a tense and widely meteoric abdomen, the presence of air-fluid levels, normal kidneys, absence of free fluid in the abdomen. The CT showed a fluid collection of about 7 cm diameter between the bladder and rectum. The explorative laparotomy found a small fissuration of the posterior wall of the bladder. For his severe conditions, the patient died a few hours after surgery, in intensive care unit. Although it is a rare event, since 1980, 177 cases of spontaneous rupture of the bladder are reported in the literature. Their causes may be essentially divided into two groups: for increase of intravesical pressure; or for weakening of the bladder wall. In most cases, the spontaneous rupture of the bladder takes place in presence of a urothelial neoplasm or after radiation therapy of the pelvic organs. The etiology of spontaneous rupture of the bladder in our case does not relate to a bladder tumor or radiotherapy. It may have been caused by repeated episodes of acute retention of urine with extreme bladder distension up to 3 liters. It is not easy to think of a bladder perforation in patients presenting signs of peritonitis without a history of bladder cancer or pelvic radiotherapy. A CT with intravesical contrast medium could help the diagnostic orientation.