The object of this operation is the reconstruction of the bladder and urethra in a nearly normal position, together with a restoration of normal functional activity. The main feature is the fixation of the base of the bladder to the pelvic floor after having exposed it by the perineal route. As a result of this procedure it is placed in a nearly normal position, and intra-abdominal pressure is exerted on its vertex instead of on its posterior wall, as is usual in cases of exstrophy. This having been accomplished, a recurrence of its extroversion is impossible. Up to the present time, the best results have been obtained by transplanting the ureters, or the ureters and trigon, into the colon or rectum. This procedure, under the best conditions, shows a high mortality rate, and there is great danger of ascending pyelonephritis. Previous attempts at reconstruction of the exstrophied bladder have been