Our objective was to determine the usefulness of intraoperative rigid endoscopy in detecting incompletely removed cholesteatomas, and to learn whether "second-look" procedures are still needed in children. We used 30 degrees, 2.7-mm endoscopes to evaluate the middle ears of 14 children (29 procedures) with cholesteatomas once all visible disease had been removed under the operating microscope. If residual cholesteatoma was seen, removal continued until all disease visualized with the endoscope was removed. If the cholesteatoma was not removed intact, planned exploratory surgery was performed. The rigid endoscope detected incompletely removed cholesteatomas at surgery in 7 of the 29 cases (24%). In 2 of the 11 cases (18%) judged free of cholesteatoma by both otomicroscopy and otoendoscopy, residual disease was found at planned exploratory procedures. While otoendoscopy is clearly useful in detecting incompletely removed cholesteatoma, a substantial rate of residual disease following "complete" removal suggests the continued need for planned exploratory procedures.