This study sought to characterize the frequency and causes of adverse drug events leading to emergency department visits in children. In contrast to adults, the majority of medication overdoses in children were due to unsupervised, accidental ingestions, while medication errors accounted for less than 15% of cases. Errors involving over-the-counter medications were more common than prescription medications, and the most common error was administering the wrong dose. Low health literacy is tied to misunderstanding prescription drug instructions, and a prior study successfully used pictogram-based education to reduce dosing errors in children. The study likely underestimates the true incidence of adverse drug events in children, as most cases are managed by poison control centers without requiring visits to a physician.