Education for sustainable development in universities provides the university's community (i.e. students, administrative and academic staff) with the skills and capabilities needed to contribute to the achievement of sustainable development. Education for sustainable development has been introduced into curricula, research, outreach activities and campus operations. Several tools exist nowadays to assess this incorporation. Most of them are focused on the environmental aspect of campus operations and within academic issues but do not consider the entire system. This research aimed to propose an integration of sustainability throughout the university as a system, considering existing tools and frameworks, and proving the theoretical proposal in an empirical context. Thus, this paper focuses on sustainability from a whole-institution perspective, analysing the university as a system conformed of two subsystems, the academic and the administrative. The research used a sequential, mixed-method. The quantitative phase undertook a literature review using bibliometric and content analysis, followed by a qualitative phase using the thematic analysis method to develop the University Sustainability concept. The University Sustainability analysis integrated education for sustainable development aspects for the academic subsystem and the corporate sustainability paradigm for the administrative subsystem. Consequently, a sustainability measurement scale for the University Sustainability concept was developed and proved using the exploratory factor analysis. The survey was applied to directors, academic and administrative staff, and under and post-graduate students of two private universities located in Medellin, Colombia. A total of 1799 useable responses were collected and analysed with SPSS software. The analysis’ outcome exposed all factors loaded above 0.40, and overall, the alpha coefficient was 0.930. Results revealed the reliability and validity of the instrument. Hence, the University Sustainability concept was validated, and its measurement scale is suitable to be used in assessing the sustainability of universities holistically. The evidence from the studied universities shows the relevance of corporate sustainability and social issues in the developed University Sustainability concept.