Spontaneous rupture of the urinary bladder is an uncommon, but important, cause of generalized peritonitis. It is a surgical emergency which may be rapidly fatal if diagnosis and treatment are delayed. Bladder disease or obstruction, coupled with a sudden increase in intra-abdominal pressure usually accounts for the rupture. Characteristic symptoms are acute lower abdominal pain followed by generalized peritonitis. In most cases, the rupture is intra-peritoneal.