Injuries to the bladder are not common, as Keyes1points out, because of the protection afforded it by the bony framework of the pelvis. Rupture of the bladder may be either spontaneous or traumatic in origin. Caulk reported four cases of spontaneous rupture in patients with preexisting bladder lesions. It is generally agreed that the normal bladder will not rupture spontaneously. Automobile accidents are one of the chief offenders and were the causative agent in five of the seven cases reported here. The sixth case was due to a blow to the lower portion of the abdomen from a saddle horn while the patient was riding horseback. The seventh was the result of falling prone while the patient was chasing a truck. Bacon and LeCount2reported forty-two cases (11 per cent) of fractured pelvic bones in 383 deaths from automobile accidents. Three cases of perforation of the bladder