Objective: Identify demographic variables related to emergency department (ED) returns, and analgesic administration in the ED for postoperative pain after adenotonsillectomy (T&A). Study Design: Pediatric Health Information System (PHIS) database analysis. Methods: Forty-seven children's hospitals included in the PHIS database were queried for all ED visits within 30 days of surgery with a diagnosis of acute postoperative pain (n = 2459) from 2014 to 2015. The subset of postoperative T&A patients (n = 861) was further analyzed for variables associated with return, and for pain management strategies, specifically opioids, employed by the ED. Results: Of the 2459 pediatric patients returning to the ED for acute postoperative pain, the largest subset included T&A patients (n = 861, 35%). Patients were seen an average of 4 days (SD 2.4) after their surgery. ED administration of opioids was not associated with gender, race, surgical diagnosis, or ethnicity. The rate of opioid administration by the ED increased with advancing age of the children analyzed (P = .01). The incidence was also higher for those with commercial versus Medicaid insurance carriers. A total of 204 (23.7%) patients received opioids while in the ED, 439 (51%) received both opioids and non-opioids, and only 51 (5.9%) received no pain medication. Conclusion: T&A patients make up the largest subset of patients returning to the ED for postoperative pain. A total of 74.7% of patients receive opioids, either alone or in combination with non-opioids, on return to the ED. ED opioid administration was associated with older age of the child and payer, but not with gender, race, surgical diagnosis, or ethnicity. Level of Evidence: 4.