Sphincter reconstruction using the gluteus maximus muscle was attempted in a 9-year-old boy who had been incontinent following surgery for the high type of anorectal malformation. Anorectal function following this procedure was assessed by anorectal manometry, defecogram, and electromyography. Postoperative function improved from Kelly 1 (poor) to Kelly 3 (fair). Adequate anorectal pressure difference and good voluntary contraction were documented one year after surgery. A defecogram one month postoperatively showed the presence of an empty segment which had not been noted before. Tonic activity at rest, which had not been present before, was found both one month and one year after surgery. These results indicate that the gluteus maximus muscle maintains some function as a newly created anorectal sphincter. In the present study, the patient was examined periodically for one year after surgery. Further follow-up studies are necessary.