OBJECTIVE: To estimate the incidence of tympanostomy tube sequelae based on systematic review of published case series and randomized studies. DATA SOURCES: English-language MEDLINE search from 1966 through April 1999 with manual reference search of proceedings, articles, reports, and guidelines. STUDY SELECTION: Cohort studies with otitis media as the primary indication for tube placement. DATA EXTRACTION: Two reviewers independently extracted data from 134 articles. DATA SYNTHESIS: Transient otorrhea occurred in 16% of patients in the postoperative period and later in 26%; recurrent otorrhea occurred in 7.4% of patients and chronic otorrhea in 3.8%. Sequelae of indwelling tubes included obstruction (7% of ears), granulation tissue (5%), premature extrusion (3.9%), and medial displacement (0.5%). Sequelae after tube extrusion included tympanosclerosis (32%), focal atrophy (25%), retraction pocket (3.1%), cholesteatoma (0.7%), and perforation (2.2% with short-term tubes, 16.6% with long-term tubes), Metaanalysis showed that long-term tubes increased the relative risk of perforation by 3.5 (95% CI, 1.5 to 7.1) and cholesteatoma by 2.6 (95% CI, 1.5 to 4.4), Similarly, intubation increased the relative risk of tympanosclerosis by 3.5 (95% CI, 2.6 to 4.9) and focal atrophy by 1.7 (95% CI, 1.1 to 2.7) over nonintubated control ears (baseline tympanosclerosis and atrophy rates of 10% and 14%, respectively). CONCLUSIONS: Sequelae of tympanostomy tubes are common but are generally transient (otorrhea) or cosmetic (tympanosclerosis, focal atrophy). Nonetheless, the high incidence suggests a need for ongoing otologic surveillance of all patients with indwelling tubes and for a reasonable time period after tube extrusion. Long-term tubes should be used on a selective and individualized basis.