Environmental education is essential to ensure the quality of the environment for sustainable development. By providing knowledge to students, it is hoped to promote awareness and develop a positive attitude towards the environment which result in good student behaviour. This study was conducted on the Sustainable Science students to reveal their knowledge, attitudes, and practices towards the environment according to year of study. Besides, the relationship between the knowledge, attitude and practice of SEL students towards environment were also examined. The survey was conducted using a quantitative approach involving 128 respondents (n = 128). The data from this study were analysed using Kruskal-Wallis and Spearman’s Rho Analysis using SPSS version 20.0 software. Based on the Kruskal-Wallis One-Way ANOVA results, the knowledge, attitude and practice were statistically significant with P value below than 0.05 for all cases. The results show that SEL students including the alumni have a high level of knowledge while satisfactory level for attitude and practices on the environment. The study also found that there was a correlation between knowledge, attitude and practice towards environment. However, this correlation was different between year of study. It was found that the Alumni and Year Four has a higher knowledge, attitude and practices towards the environment. Thus, environmental education subject is important in order to build environmental concern among the students and also to encourage their attitude and practices towards more environmental friendly behaviour.