Five children with urinary incontinence were operated with a new method involving free autogenous muscle transplantation. Before transplantation a skeletal muscle (extensor brevis of the foot) is denervated and, 2 weeks later, it is transplanted and placed as a U-sling around the urethra in close contact with normally innervated muscles, which act as reinnervation sources. All patients showed improvement of continence and increasing bladder capacity from about 2 months after transplantation. Postoperative cine-micturition studies clearly demonstrated the functional properties of the transplanted muscle and estimation of urinary flow rate showed no signs of infravesical obstruction.