We conducted a study to determine how accurate various ENT specialists were in estimating the size of 100 tympanic membrane (TM) perforations with standard otoscopy. The specialists included, in descending order of rank, 2 Consultant Surgeons, 2 Senior Registrars, and 2 Registrars, all of whom had confirmed good vision. We compared their estimates, which were made independently and expressed as a percentage of the total area of the TM, with exact measurements calculated with computer-based video-otoscopy. We found that the video-otoscopic calculations were far superior to the estimates of the specialists, even the most experienced Consultants (p < 0.01). We recommend that video-otoscopy be used whenever possible.