Background: Initial treatment of acute upper respiratory infection (AURI) should not include antibiotics because most AURIs are caused by virus. However, the prescription rate of antibiotics in Korea is higher than in any other countries. Inappropriate use of antibiotics in Korea accelerated the emergence of antibiotics resistance and increased the social and economic burden. The objective of this study was to investigate the factors related to antibiotics use for the AURI among children-adolescents and adults. Methods: This study analyzed the Health Insurance Review and Assessment Service-National Patient Sample data which was nationally representative sampling stratified by sex and age. Results: The influencing factors of antibiotics use for AURI are gender, age, types of medical security, primary disease, existence of concomitant disease, treatment seasons, first visit or revisit, indicated specialty, types of medical institution, and location of medical institution. Conclusion: The results showed health policy makers are required to place more efforts to resolve inappropriate antibiotics use. Especially they need to establish a health policy to reduce the gap between areas and specialties and recommend standardized clinical guidelines according to the subgroup code of AURI and the age group of patients.