Conducting sustainability impact assessment enables higher education institutions (HEIs) to measure progress toward achieving their sustainability goals at the superordinate macro or systems level, at the (inter-) organizational meso level which includes relationships with various stakeholders, and at the individual micro-level encompassing individual stakeholder goals. Participatory impact assessments involve various stakeholders gathering data on the potential impacts of measures and providing multi-perspective advice to HEI decision-makers which benefits well-balanced decisions. The involvement of stakeholders also serves to enhance relationships with stakeholders, which helps to enhance legitimacy of measures and benefits more effective implementation of measures. This chapter presents various evaluation instruments for assessing the impact of sustainability transformations at HEIs. The aim is to highlight the significance of sustainability impact assessment in HEIs and to emphasize that multiple frameworks may be employed.