ABSTRACTObjetive:Studies have shown that the practice of self-medicating children occurs worldwide and is independent of the country’s economic level, medication policies, or access to health services. This study aimed to estimate and characterize the prevalence of self-medication in the Brazilian population of children aged up to 12 years.Methods:We analyzed the data of 7528 children aged up to 12 years whose primary caregivers responded to the National Survey on Access, Use and Promotion of Rational Use of Medicines in Brazil (PNAUM), a cross-sectional population-based study conducted in 245 Brazilian municipalities. The prevalence of self-medication was defined as the use of at least one medication without a doctor’s or dentist’s indication 15 days before the interview.Results:The prevalence of self-medication was 22.2% and was more frequent in older children belonging to poorer families and without health insurance. The acute conditions for which there was a higher frequency of self-medication were pain, fever, and cold/allergic rhinitis. Analgesics/antipyretics stood out among the most used medications for self-medication.Conclusions:The prevalence of self-medication to treat acute conditions was high in Brazilian children sampled in PNAUM, emphasizing the management of common symptoms such as pain, fever, and cold/allergic rhinitis in this age group. These findings reinforce the need for educational actions aimed at parents and caregivers.