The purpose of this article is to introduce scientific methods of medical auditing that can be used with common understanding by hospitals and doctors whose work is to be audited and by persons or agencies making audits. Methods for abstracting and classifying cases, criteria by which individual cases can be judged, and standards by which satisfactory performance can be measured are described and illustrated by actual experience. In the interest of brevity, the descriptions have been limited to a few kinds of female pelvic surgery, but similar methods for auditing other surgical operations and the diagnosis and treatment of various diseases will be described elsewhere. Medical audit is defined as the evaluation of medical care in retrospect through analysis of clinical records. It does not relieve the hospital staff of the daily necessity of supervising, educating, and assisting its members in providing good professional care; in fact, by its exposure