OBJECTIVES: Using data from the Slone Survey, we sought to define the prevalence of over-the-counter and prescription medication use among US children <12 years of age and to determine the prevalence and patterns of use of the most commonly used medications. METHODS: The Slone Survey was a random-digit-dial telephone survey of medication use in the previous 7 days for a representative sample of the US population. Between February 1998 and April 2007, we enrolled 2857 children 0 to 11 years of age from the 48 contiguous US states. RESULTS: The survey response rate was 61%. Overall, 56% of children had used >= 1 medication product in the 7 days preceding the interview, with 15%, 7.1%, 3.1%, and 1.9% taking 2, 3, 4, and >= 5 medications, respectively, during that time period. Twenty percent of children took >= 1 prescription-only medications, but <6% used >= 2 prescription-only drugs within a given week. Fewer than 0.5% of children were reported to have used any particular herbal product. The most commonly used over-the-counter medication products were acetaminophen alone, multivitamins, and ibuprofen alone. The most commonly used prescription-only medications across all age groups were amoxicillin, albuterol, and multivitamins with fluoride. The most commonly consumed active ingredients (excluding vitamins) were acetaminophen, iron, ibuprofen, and various cough/ cold ingredients (pseudoephedrine, dextromethorphan, and various first-generation antihistamines). CONCLUSIONS: The majority of US children <12 years of age use >= 1 medication product in a given week. The preponderance of pediatric medication exposure involves over-the-counter products. Pediatrics 2009; 124: 446-454