Tonsillectomy is a common and painful procedure often indicated for children with obstructive sleep apnea (OSA) who are at risk for opioid-related toxicity. Whether parents whose children have OSA understand the risks of opioids is unknown. The purpose of this study was to examine whether parents whose children have OSA have greater opioid risk understanding and would be less likely to give an opioid to a child exhibiting oversedation compared to parents whose children do not have OSA. The study design was a secondary analysis of a prospective observational study. The study was conducted in a large academic, tertiary care children's hospital in the Midwest. 224 parents whose children with or without OSA underwent tonsillectomy with/without adenoidectomy were included. Parents were assessed for opioid adverse event understanding and then made decisions to give/withhold opioids for a child exhibiting adverse effects. After discharge, parents recorded all opioid doses they gave their child. There were no differences in opioid understanding between OSA and non-OSA groups, and nearly half in both would give an opioid to the child exhibiting oversedation. Similar amounts of opioids were given at home. OSA did not predict parents' opioid decisions; however, around-the-clock instruction predicted greater opioid use at home. Parents whose children had OSA had a similar understanding of opioid-related oversedation compared to other parents, and half would give a prescribed opioid when signs of oversedation were present, suggesting a need for improved understanding and recognition of this sign of toxicity, and of what to do should this symptom present.