To determine how often Food and Drug Administration (FDA)-approved age-specific prescribing guidelines were followed in pediatric emergency department (ED) patients, the charts for all children presenting to a university hospital pediatric ED during a 30-day period were reviewed. Of the 359 children who received drug therapy in the ED, 43% received one or more drugs not approved for use at the patients' respective ages. Of 296 children discharged with one or more prescriptions, 16% received a drug prescribed outside of FDA-approved guidelines based on age criteria. Overall, 34% of children who received drug therapy in the ED or by prescription did not meet age-specific FDA-approved prescribing guidelines. The medications most commonly given outside FDA-approved guidelines were bronchodilators, benzodiazepines, and narcotic analgesics. Drug therapy in pediatric ED patients often falls outside FDA-approved prescribing guidelines.