Background: The Eurobarometer 2010 report on antimicrobial resistance included a survey on the knowledge of Europeans about antibiotics. Austria was ranked at the bottom of the EU27 countries. Based on these alarming results, it was the aim of this study to analyse demographic characteristics of patients and general practitioners in Austria to assess possible predictors for this outcome as well as to assess the main source of information related to antibiotics. Methods: This cross-sectional study was conducted within the context of the European APRES project. An additional 12-item questionnaire was developed asking for the knowledge about antibiotics, demographic data and the source of information. Statistical analyses included subgroup analyses and linear mixed regression models. Results: Overall, 3280 questionnaires were analysed. On average, 2.78 (standard deviation 1.69) out of the six knowledge questions were answered correctly. The main predictors for a low knowledge score were low educational level, age, speaking another language than German and male sex. In all, 55.6% of the participants marked the general practitioner as main source of information. However, the source was less important for the knowledge score than their highest educational level. Conclusion: The Eurobarometer report result for Austrians could be confirmed and important associations and predictors could be identified: a multifaceted and evidence informed strategy is needed to improve the situation, which should both focus on target-group–specific interventions at the individual level to increase the knowledge of people with the highest needs as well as on strengthening the primary health care and educational sector at the system level.