To investigate the natural history of pediatric tympanic membrane perforation using an existing clinical database, with the aim of defining the time beyond which a perforation is unlikely to close naturally. Retrospective cohort study. Tertiary center. A database of pediatric ear, nose, throat, and audiology consultations containing 20 years of data was analyzed. A total of 2865 episodes of perforation were followed, with all cases of surgical reconstruction excluded. Cases of perforation after ventilation tube extrusion were tagged. Statistical techniques including survival analysis were used. Time from diagnosis of perforation to diagnosis of closure, in years. There was a predominance of perforations in boys (59.1% versus 40.9%). Time to closure increased by 7% for each 1-year increase in age at diagnosis. Time-to-closure curves for children older than 12 years diverged considerably from those for younger children after approximately 18 months. Centiles of time to closure were calculated for each 1-year age band. After 2.5 years of follow-up, rates of closure were 90% in children diagnosed younger than 7 years and 75% in children diagnosed between the age of 7 and 12 years. No significant difference was found in time to closure between boys and girls, left-sided and right-sided perforations, or in ventilation tube-related perforations and others. Comparison of membranes suffering a first perforation with those suffering a second perforation suggested a borderline significant time-to-closure disadvantage for first perforations. When faced with the clinical question of what period of watchful waiting would be appropriate in monitoring a perforated tympanic membrane, before intervention may reasonably be recommended; there seems to be little advantage in waiting longer than 2.5 years.