This study explored university students' pro-environmental knowledge and self-reported pro-environmental behaviours, and the influence of environmental education on their knowledge, beliefs and behaviour. This study also investigated the difference in forming pro-environmental behaviours across gender types and academic majors. The Theory of Planned Behaviour was used to frame the study and to understand if knowledge and beliefs translate into pro-environmental behaviours. A mixed-method approach was taken to achieve the research objectives. The participants comprised of 226 undergraduate students from a leading university in Saudi Arabia. A questionnaire and interview protocol were used to collected data. Descriptive statistical analysis, t-tests, One-way ANOVA, post-hoc tests and thematic analysis were used to analyse the data sets. The results of the study showed that knowledge gained from formal environmental education does not translate to pro-environmental behaviours. This study highlights the need to promote pro-environmental behaviour in university settings by eliminating obstacles to pro-environmental actions.