Objectives: To investigate fear of legal claims and defensive behaviours among specialists in infectious diseases (ID) and clinical microbiology (CM) and to identify associated demographic and professional characteristics. Methods: AntibioLegalMap was an international cross-sectional internet-based survey targeting specialists in ID and CM. Three variables were explored: fear of legal liability in antibiotic prescribing/advising on antibiotic prescription; defensive behaviours in antibiotic prescribing; and defensive behaviours in advising. A multivariable logistic regression analysis was performed to identify factors significantly associated with each of the three variables. Results: Eight hundred and thirty individuals from 74 countries participated. Only 0.4% (3/779) had any kind of condemnation for malpractice related to antibiotic prescription. Concerning the fear of liability, 21.2% (164/774) of respondents said they never worried, 45.1% (349/774) sometimes worried and 28.6% (221/774) frequently worried when prescribing/advising on antibiotic prescription. Being female, younger than or equal to 35 years and aware of previous cases of litigation were independently associated with fear. Most respondents (85.0%, 525/618) reported some defensive behaviour in antibiotic prescribing. These behaviours were independently associated with being younger than or equal to 35 years and sometimes or often worried about liability. Similarly, 76.4% (505/661) reported defensive behaviours in advising. These behaviours were associated with being sometimes or often worried about liability. The preferred measures to reduce fear and defensive behaviours were having local guidelines and sharing decisions through teamwork. Conclusions: A significant proportion of specialists in ID and CM reported some form of defensive behaviour in prescribing or advising to prescribe antibiotics. Defensive medicine should be considered when implementing antibiotic stewardship programmes.