Recognizing the increasing importance of sustainable environment, this research explored visitors’ pro-environmental decision-making process in an urban park context. This study investigated the relationships among attitudes, subjective norms, perceived behaviour control, positive and negative anticipated emotions as well as behavioural intentions. The results suggest that positive anticipated affects positively influenced low-effort and high-effort pro-environmental behavioural intentions. In addition, positive anticipated affects mediated the relationship between cognitive factors and behavioural intentions. Interestingly negative anticipated affects did not influence behavioural intentions. Further analysis revealed subjective norm was the strongest predictor of intentions, especially the low-effort pro-environmental behavioural intentions. The research advances the conceptual understanding of the role of each construct in generating park visitors’ intentions to perform environmentally responsible behaviours while visiting an urban park.