The Theory of Planned Behaviour has been used to investigate the likelihood that anaesthetists will routinely perform three violations of safety guidelines. The three violations were: failing to visit patients before surgery, failure to perform pre-anaesthetic equipment checks and the silencing of alarms during anaesthesia. These suggested violations arose from discussions with the Medical Defence Union. In forming the intention not to perform these violations, anaesthetists are most influenced by their normative beliefs about the violation, i.e. the opinion they believe a group of peers and other significant other people would hold about them performing the violation. The next most influential factor is their personal norms, i.e. beliefs that the individual has about whether the violation is really right or wrong, followed by behavioural beliefs, i.e. beliefs about the consequences of performing the violation, and control beliefs, i.e. beliefs about how much control they have over performing the violation. The results show that the more intense the anaesthetists' belief that the violations were important, the less likely they were to violate, except for the case of alarm silencing. This result suggests that there may be a basic lack of confidence in the reliability of audible alarms that undermines their utility.