Objectives: To explore relationships between age and sequelae in two groups of children treated with tympanostomy tubes for chronic otitis media with effusion (OME). Study Design: Cross-sectional study of sequelae among children, adolescents, and adults at 4 years and 9 to 23 years after tympanostomy tube treatment. Methods: Group I was examined with otomicroscopy, tympanometry, and audiometry two to four times a year as part of a prospective study, and they were evaluated 4 years after initial tube treatment for this study. Group II received tubes while participating in a chronic OME study, but participants were not followed prospectively after treatment. Nine to 23 years after tube treatment, they were examined with otomicroscopy, tympanometry, and hearing screening. Results: Among the 5- to 28- year-old subjects, cholesteatoma (≤1%) and perforation (≤2%) were rare. In Group I, tympanosclerosis increased with age (P < .01), and OME (flat tympanograms) decreased with age in Group II (P < .01). The older cohort was more likely to have severe retractions (18% vs. 4%, P = .02), hearing loss (21% vs. 10%, P < .01), and severe atrophy (24% vs. 0%, P < .01) than the younger cohort, but they were less likely to have fiat tympanograms (2% vs. 12%, P < .01). Conclusions: Although OME became less prevalent with age, important sequelae (severe atrophy, severe tympanic membrane retraction, hearing loss, cholesteatoma, and chronic perforation) may develop in children with chronic OME as they become adolescents and young adults. Long-term prospective studies are important in defining the progression of sequelae in these children.