Posterior sagittal anorectoplasty (PSARP) is a new technique for the repair of high anorectal malformations. It is based upon complete exposure of the anorectal region by means of a median sagittal incision that runs from the sacrum to the anal dimple, cutting through all muscle structures behind the rectum. It was learned through this procedure that the external sphincter is a functionally useful prominent structure. No puborectalis sling, as such, could be identified. It was possible, however, to recognize a muscle continuity from the skin to the sacral insertion of the levator ani. Since it is impossible to pull the generally ectatic rectum through without destroying the muscle structures present, the rectum must be tapered to allow suturing the muscle behind it. In all these anomalies, the rectum and urethra (or vagina) are very closely joined, sharing a common wall, and their separation calls for extensive exposure. A number of technical details clarified in the course of applying the procedure in 54 patients are fully discussed. This approach also proved to be very successful in the management of two patients with rectocloacal fistula, two with rectal atresia and two with stenosis. Colostomy has been closed in 27 patients and fecal continence may be described as excellent, except in those patients with severe sacral anomalies, and unquestionably superior to that obtained by us with other techniques.