Integrating sustainable development into higher education is essential to reach a sustainable future; accompanied with level of knowledge, increasing level of motivation of university students is also crucial since motivation affects their ways of sustainable behaviour. Therefore, this study aimed to explore university students' reflections about their level of knowledge on sustainability and their ways of integrating sustainability principles into their profession and daily life. Thus, we attempted to investigate university students' level of self-efficacy beliefs on integrating sustainability into their profession and daily life after completing a sustainability course. However, since there is no specific instrument to evaluate university students' self-efficacy beliefs on this subject, we adapted the instrument (originally developed by Enochs & Riggs, 1990) to determine university students' self-efficacy beliefs on integrating sustainability into profession and daily life and used the instrument to explore our research questions. Besides, we used students' essays and self-reports in order to evaluate their conceptions on sustainability. The implementation was realised with 113 university students studying at a state university in Ankara, Turkey). According to the exploratory factor analysis results, two dimensions emerged as Daily Life Efficacy and Profession Efficacy to integrate sustainability. The results showed that university students who attended the sustainability course have relatively high personal self-efficacy beliefs towards integrating sustainability into their daily life. Nevertheless, although they reported that they have enough background knowledge on sustainability and have high self-efficacy, evaluations of the students' essays on the definition of sustainability showed that they do not hold a holistic understanding.