One of the main objectives of higher education for sustainable development is to nurture holistic conceptions of sustainability in students, so that they can use sustainability as an approach to analyze and solve complex problems in their future professional fields. Existing studies have shown that students differ substantially in how relevant they consider the concept of sustainable development to their future careers. Previous studies have identified socio-demographic characteristics, disciplinary background and past experiences with sustainability education as potential influencing factors. To date, the relationships between one's own "understanding" of sustainability (sustainability conception) and the importance students attach to sustainability has hardly been investigated. This case study offers a first systematic examination of how the perceived professional relevance of sustainability is influenced by different individual characteristics and sustainability conceptions. Based on data from a recent survey of n = 1364 first year undergraduate students from 14 different major subjects, our findings indicate that in addition to the previously reported individual characteristics like sex and academic affiliation, sociocultural sustainability conceptions are an important influential factor for the perceived importance of sustainability for their professional contexts. However, the regression analysis shows that the model based on predictors found in the literature lacks incremental power. This paper unveils that further research is needed on the underlying factors that explain the strength of perceived relevance of sustainability in students and that these influences need to be taken more into account in curriculum development.