This study evaluates the endosonographic patterns of the anal sphincter after sphincteroplasty to define specific postoperative findings and to identify factors related to clinical outcome after sphincter repair. Thirty-one incontinent patients (29 women, two men; mean age = 57 years) who underwent surgical repair for an external sphincter defect were studied postoperatively by endosonography. Twenty patients were found to improve after surgery. Postoperative endosonograms showed specific images: direct visualization of the surgical process was represented by the "overlapping sign" in 17 cases and the "end-to-end suture" in four cases. These echographically favorable cases were associated with improvement after surgery in 18 of 21 patients (p < 0.005). Persistent defects were reduced in five patients and unchanged in five other patients and were associated with poor outcome in eight of 10 patients (p < 0.005). Postoperative endosonography of the external anal sphincter presented some specific endosonographic aspects. The association between anal endosonographic findings and clinical outcome suggests the use of this procedure to assess patients following sphincteroplasty.