The aim of this study consisted in assessing knowledge, attitudes and behaviours concerning various aspects of sustainable development in a group of Portuguese university students and measure the influence of area of study for admission to higher education on this dimensions. The collection of data was undertaken via the completion of a questionnaire, which was designed to include the following dimensions: knowledge, attitudes and behaviours. This initiative took place in the 2016/2017 academic year and the focus/target group for was constituted by 168 prospective elementary teachers. The validation procedures of the questionnaire confirmed its three-dimensional structure. The results obtained showed the existence of very favourable knowledge and attitudes regarding sustainable development. Behaviours proved less favourable than the other two dimensions. In addition, the results show that respondents' area of study for admission to higher education has no influence regarding knowledge, attitudes and behaviours concerning sustainable development. Finally some implications for teachers and students are raised and discussed.