Negative visitor behaviour in zoos such as banging, shouting and feeding animals are unwanted, but under-studied, visitor actions. It is not known how prevalent negative behaviour is, which species or enclosure type receives the most negative behaviour or how these behaviours affect zoo-housed animals. In this study, a comprehensive assessment of negative visitor behaviour, using an innovative methodology, was conducted at 25 different enclosures at Fota Wildlife Park, Ireland. Additionally, animal activity level and out of sight behaviour was observed.