To define the association between pre-operative general emergency department visits, gender, and pre-operative diagnosis with post-operative emergency department return following adenotonsillectomy.Retrospective chart review of 1468 pediatric patients who underwent adenotonsillectomy at a tertiary pediatric hospital between 2011 and 2013.There was a significant relationship between patients who visited the ED pre-operatively, 25% (N=96) returned to the ED post-procedure, compared to 10% who did not have a pre-operative ED visit. There was an overall significant relation between having a pre-operative visit (χ 2 =53.6, df=1, p<0.001), female gender (female=56.9%; male=43.1%; χ 2 =4.2, df=1, p=0.04), and having a preoperative diagnosis of recurrent strep tonsillitis (OSA and RST=18%; RST=17.5%; OSA=11.8%; χ 2 =12.8, p=0.002) and having a post-operative ED visit.Generalized pre-operative visits along with gender and diagnosis of recurrent streptococcal tonsillitis were found to be positively associated with post-operative ED visits for common post-operative complaints.