BACKGROUND: The Thailand National Strategic Plan on Antimicrobial Resistance (AMR) 2017-2021, endorsed by the Thai Cabinet in 2016, aims to increase public knowledge about antibiotics and AMR awareness by 20% by 2021. This study assesses the prevalence of antibiotics use, clinical indications and sources; knowledge and access to information related to antibiotics and AMR; and factors related to level of knowledge and access to information among Thai adult population. METHODS: An AMR module was developed and embedded into the 2017 Health and Welfare Survey; a cross-sectional, two-stage stratified sampling, nationally representative household survey carried out biannually by National Statistical Office. The survey applied a structured interview questionnaire. The survey was conducted in March 2017 where 27,762 Thai adults were interviewed of the AMR module. Data were analyzed using descriptive and inferential statistics. RESULTS: The one-month prevalence of antibiotic use was 7.9% for three common conditions; flu (27.0%), fever (19.2%) and sore throat (16.8%). The majority of antibiotics (70.3%) were provided by public or private healthcare facilities, and 26.7% by pharmacies. Thai adults have low levels of knowledge about antibiotics; only 2.6 gave correct answers to all six statements related to antibiotics, while 13.5% gave wrong answers to all six statements. A few factors associated with knowledge and having received information on antibiotics were assessed. People who have higher education levels, and belong to richer wealth quintiles, and receive antibiotics and AMR information have significantly higher levels of knowledge about antibiotics. In the last 12 months, only 17.8% of respondents had heard information about the proper use of antibiotics and AMR; mostly from doctors (36.1%), health workers (24.8%) and pharmacists (17.7%). CONCLUSIONS: There is a large gap of public knowledge about the use of antibiotics. The main communication channel is through healthcare professionals, which indicates they are key persons in communicating information about the proper use of antibiotics to the public.