The research analysed the behaviour of visitors to protected natural sites on the island of Tenerife and described the main characteristics of visitors to these areas. Visitors completed anonymous research questionnaires based on a model that combines the Theory of Planned Behaviour with other elements of behavioural analysis, and using this research tool, the factors influencing visitors' resulting pro-environmental behaviour were analysed. Visitors were also asked how they perceived the situation regarding litter management in the natural sites and how they were influenced by the education provided by the management of the natural park. The research results confirm the importance of the influence of environmental education on people's environmental awareness. It was found that awareness of the consequences of behaviour significantly influences personal norms and attitudes, and these in turn have the greatest impact on the resulting pro-environmental behaviour of visitors. A protected natural area can have an educational role, but it is also important to enable visitors to behave in an environmentally conscious manner, for which the provision of appropriate conditions (sufficient bins, the ability to sort waste, etc.) is needed. The research results also indicated that pro-environmental behaviour is influenced by perceived behavioural control, i.e. how difficult it is for visitors to behave in a certain way in a given environment.