OBJECTIVE: Determine the prevalence of synchronous airway lesions (SALs) in children younger than age 3 years undergoing adenoidectomy or adenotonsillectomy for sleep-disordered breathing (SDB) at Children's Memorial Hospital. DESIGN: Case series with chart review. SETTING: Tertiary care pediatric hospital. CHILDREN: One hundred ten children 3 years of age or younger who underwent adenoidectomy or adenotonsillectomy along with a full-airway evaluation that included flexible fiber-optic laryngoscopy, direct laryngoscopy, and rigid bronchoscopy for SDB from January 2003 to January 2009. OUTCOME MEASURES: Prevalence of SALs and rate of SALs that required intervention. RESULTS: Sixty-seven percent of children were found to have at least 1 SAL. Four children required surgical intervention for a SAL. There was no significant difference in preoperative respiratory distress index (RDI) between children with normal airway examinations compared with children with a SAL. There was no significant difference in the rate of SALs between children younger than 18 months old and those 18 to 36 months old. CONCLUSIONS: There is a high incidence of SALs in children younger than 3 years old with SDB. There was no significant difference in the rate of SALs in children younger than 18 months old compared with children 18 to 36 months old. The RDI determined by a polysomnography was not predictive of the presence of a SAL. Tracheal cobblestoning was the most common SAL discovered.