This is a report on 16 patients with epispadias of grades II to IV and on 35 patients with exstrophy of the bladder, grades III and IV. The following surgical treatment was carried out: in children with epispadias, simple closure of the urethra in one case, neck of the bladder plasty according to Young-Dees in two cases, the method after Thiersch-Duplay in three cases, whereas four patients were treated after Williams, five after Johnston and one patient after Ombrédanne in reverse. Seven additional operations were done mainly for prepuce correction and closure of fistula after urethroplasty. Three of the 16 patients were continent already before the operation. 4 children were partially continent. Two of these showed improved continence, thus achieving prolonged periods of dryness. 9 children remained incontinent. Hence, free muscle transplantation to the bladder was performed in four patients. A total of 45 operations were performed on children with exstrophy of the bladder. Of these, 12 concerned primary closure of bladder; in 13 cases, an ileum bladder was constructed, whereas cystosigmoideostomy was done in 5 times, uretersigmoideostomy 5 times, cutaneous ureterostomy once, rectum bladder once, and a colon conduit once. The postoperative continence performance of the 12 patients with primary bladder closure was unsatisfactory. Three children only attained periods of dryness up to two hours; 5 remained completely incontinent, whereas in 4 it was subsequently necessary to construct a urinary passage into the intestine by means of an ileum bladder in 2 cases, a colon conduit in one case, and ureterosigmoideostomy in one case. Free muscle transplantation to the bladder was performed in two patients. Free muscle transplants were also performed on 2 children, in one case after traumatic tearoff of the urethra and in one case after iatrogenic lesion of the musculus sphincter vesicae externus in adrenogenital syndrome (AGS) according to Prader III and IV. This means that a total of eight free muscle transplants were performed. All children were primarily incontinent. Postoperatively, complete continence could be achieved in four cases, once an improvement with dry periods up to 2 hours. The two patients with bladder exstrophy remain incontinent, in one patient with epispadias the postoperative interval has been too short so far to arrive at a final judgement. It follows from the examinations that free muscle transplantation is a good method for treating urinary incontinence, the suspension effect playing an important part. However, in patients with bladder exstrophy the indication should be considered with caution.