Given that 30% to 40% of children have persistent obstructive sleep apnea (OSA) after adenotonsillectomy, we evaluated whether children with hypopnea-predominant OSA were more likely to have complete disease resolution after adenotonsillectomy than those with apnea-predominant disease. We also identified risk factors that might modify the relationship between disease resolution and polysomnographic event type (ie, hypopnea vs apnea). Case series with chart review. Tertiary pediatric hospital. Consecutive 1- to 18-year-old typically developing children diagnosed with OSA from March 2011 to December 2012 underwent adenotonsillectomy and completed pre- and postoperative polysomnography within 1 year of surgery. Fifty-eight children were included (27 female; mean ± SD: age, 5.6 ± 3.1 years; body mass index z score, 1.1 ± 1.7). Overall, adenotonsillectomy resulted in significant improvement in obstructive apnea-hypopnea index (oAHI) from 23.3 ± 40.0 to 4.3 ± 8.2 events per hour (P < .001), obstructive apnea index (5.1 ± 7.4 to 0.4 ± 0.8, P < .001), and obstructive hypopnea index (oHI; 18.1 ± 37.5 to 3.7 ± 8.1, P < .001). There was complete response (oAHI <1.0 event/h) in 24 of 58 patients (41%) but no difference by event type (P = .11). On univariate analysis, only race, sex, oxygen saturation nadir, and oHI were predictive of response to adenotonsillectomy, while multivariate analysis found that prematurity, age, oxygen saturation nadir, oHI, obstructive apnea index, and oAHI were predictive. Event type was not significant, even in a model controlling for age, race, sex, prematurity, asthma, body mass index, and baseline polysomnographic variables. This small study demonstrated no difference in disease resolution between children with hypopnea- and apnea-predominant OSA who underwent adenotonsillectomy. Additionally, adenotonsillectomy significantly improved OSA in most children, and high preoperative oAHI was associated with persistent postoperative OSA.