In recent years there has been an increase in the use of behaviour modification (BMod) approaches to safety. These interventions generally involve the observation and assessment of certain behaviours, usually those of front-line personnel. The rationale behind behavioural safety approaches is that accidents are caused by unsafe behaviours. These approaches are based on behaviourist theories, which can be summarized by 'behaviour that is strongly reinforced will be maintained'. There are reports of some successes with behaviour modification in a range of environments, including the process industries. Such approaches have a number of advantages in addition to reducing incidents, including increased communication about safety, management visibility and employee engagement. However, these programmes tend to focus on intuitive issues and personal health and safety, ignoring low probability/high consequence risks. The author proposes that the causes of personal safety accidents may differ to the precursors to major accidents and therefore behavioural safety programmes may draw attention away from process safety. Furthermore, the tendency is to focus on individuals and fail to address management behaviour, thus excluding activities that have a significant impact on safety performance. This paper discusses the usefulness of behaviour modification approaches, particularly in managing major accident hazards, and provides guidance for companies that may be considering embarking on such a programme.