Objective To assess the impact of the 2011 American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) guideline on practice patterns in obtaining preadenotonsillectomy (AT) polysomnography (PSG) for pediatric sleep-disordered breathing (SDB). Study Design Retrospective cohort study. Setting Tertiary children's hospital. Subject and Methods The study population included all patients referred to our pediatric otolaryngology clinic for consideration of AT for SDB during two 12-month time periods: before (2010-2011) and after (2015-2016) publication of the 2011 AAO-HNS guideline. Demographic, insurance, comorbidity, and Pediatric Sleep Questionnaire (PSQ) variables were assessed for association with pre-AT PSG using bivariate and multivariate logistic regression analysis. Results A greater percentage of patients underwent pre-AT PSG in 2015-2016 vs 2010-2011 (30% vs 22%, P = .001). On multivariate analysis, presence of neuromuscular disorder was the only predictor associated with pre-AT PSG in 2010 to 2011 (odds ratio [OR], 3.00; 95% CI, 1.10, 8.06; P = .03). Presence of neuromuscular disorder (OR, 2.54; 95% CI, 1.51, 4.29; P < .0001), craniofacial anomaly (OR, 2.32; 95% CI, 1.20, 4.50; P = .013), or Down syndrome (OR, 3.45; 95% CI, 1.54, 7.72; P = .003) was associated with pre-AT PSG in 2015 to 2016. Positive PSQ screen was significantly associated with decreased odds of pre-AT PSG in both time periods. Conclusion After publication of the 2011 AAO-HNS guideline, there was a significant but modest increase in pre-AT PSG utilization in children with SDB and high-risk comorbidities at our institution, consistent with AAO-HNS guideline recommendations. However, overall guideline adherence remains low and may reflect limitations in PSG testing capacity.