&NA;The purpose of this paper is to show whether there is a keyhole deformity, its surgical significance, and how often it occurred following surgery for ulcer‐in‐ano. To do this, a retrospective study, over a 16‐year period, of all patients admitted to the Ferguson Clinic with chief complaints of anal incontinence was undertaken. Of this group of patients, seven were identified as having questionable keyhole deformities, three of whom probably had classic defects. There were six females and one male. Only two of the deformities were associated with surgery for ulcer‐in‐ano. One of these was easily repaired and the other patient had a full rectal prolapse. In addition, of 186 patients undergoing fistula surgery, 77 who had posterior midline transsphincteric fistulas were studied and ten of these patients went on to complete recovery without any permanent problems resulting from severance of the sphincter. It can generally be concluded that, although there is such a defect as the keyhole deformity, it occurs only rarely, especially after surgery for ulcer‐in‐ano, and that many times it is not associated with anal incontinence.