Background: Antimicrobials use is associated with diverse secondary effects, as allergies, specific adverse drug reactions and emergence of antimicrobial resistance. Effective risk communication to the general public about their uses and potential issues is critical. In-ternational experience reveals deficient knowledge in countries without educational policies regarding this issue, but their implementation can reverse such deficit. There are scarce publications at regional and national level about these topics. Aim: To describe the knowledge and behaviors regarding antimicrobial use in adults in Santiago de Chile. Methods: We conducted a cross-sectional study through a survey in 300 people in Santiago de Chile, evaluating 4 areas about antimi-crobials: knowledge, use, behaviors, and antimicrobial resistance knowledge. Results: 297 people were surveyed with ages between 18 and 81 years old. Seventy-five percent of them were younger than 45 years old. 65% of the surveyed thinks antimicrobials works against viruses, 51% believes they work against the common cold and 32% of the population has used them without a prescription. Fifty-one percent of the sample has heard about antimicrobial resistance and 33% knows its correct definition. Conclusions: The Chilean population has an important deficit in antimicrobial knowledge and use.