The study of on-site environmentally responsible behaviours at outdoor events is important because of the negative environmental degradation that may be caused when hosting these events. Studying these behaviours is especially important at music festivals that are held in protected areas, and/or for festival managers who have an interest in controlling the events' negative environmental impacts. Despite recent interest by event managers in developing strategies to encourage attendees' environmentally responsible behaviours, this task is still a challenge because attendees may be disinterested in behaving pro-environmentally in the music festival context. Given this, event managers need to find novel ways to encourage attendees to participate more in on-site environmentally responsible behaviours.To contribute toward finding alternative ways to encourage more participation, this research investigated the major psychographic factors that influence attendees' engagement in on-site environmentally responsible behaviours at music festivals. To identify these factors, the following research activities were carried out: phone interviews with music festival managers (10 participants); two online questionnaires (pre-visit and post-visit to festivals) across multiple music festivals (1,313 and 420 participants, respectively); and on-site interviews with attendees at a three-day music festival located near an Australian national park (81 participants).The findings of this study reveal that event managers consider it important to build a proenvironmental culture into their event communities in order to capitalise on attendees' sense of community that may support environmentally responsible behaviours. The analysis also provides evidence of discrepancies between attendees' intentions to behave in an environmentally responsible way at the music festivals and their actual behaviours.Psychographic factors such as pro-environmental predisposition, self-identity as eco-friendly, festival attachment, place attachment, on-site management strategies, perceived benefits and barriers are all important contributors to attendees' on-site behaviours. Further, the study finds that some attendees exceed their intentions to behave responsibly towards the environment and that this is linked with their perceptions of the music festival's green status.Attendees also consider it important to behave in an environmentally responsible way on-site because of the benefits they perceive for the well-being of both the festival community and the environment. In terms of barriers to engaging in on-site environmentally responsible behaviours, the findings reveal that the main obstacle for attendees is the belief that their actions will not make a difference.These results are of great significance to event management settings and can contribute to the design of management strategies to encourage attendees' on-site eco-friendly behaviours.