Serious faecal incontinence due to anal sphincter damage should be treated by surgery. Graciloplasty has had limited success because the gracilis is a fast-twitch muscle and fatigues quickly. A favourable outcome in a patient who had dynamic (electrically stimulated) graciloplasty encouraged us to further assess this procedure. Gracilis muscle transposition was done in ten patients with complete anal incontinence due to anal atresia, sphincter damage, or neurogenic causes, and who had had several other unsuccessful treatments. 6 weeks after muscle transposition, intramuscular leads were implanted and connected to an implantable electric stimulator. Eight patients became continent, one patient still has a diverting colostomy, and a fistula developed in the other patient. Anal sphincter pressure improved from 35 mm Hg without stimulation to 62 mm Hg with stimulation at 8 weeks (mean increase 28 mm Hg [95% confidence interval 18, 36], p less than 0.01). Retention time of a phosphate enema increased from 22 to 281 s (mean increase 259 s [82, 436], p less than 0.01). Defaecography showed that the new sphincter was functioning. Defaecation was possible when the stimulator was turned "off" with a magnet. Dynamic graciloplasty can restore continence and it improves quality of life in faecally incontinent patients for whom other treatments have been unsuccessful.