There is a deficit of multi-site studies examining the integration of sustainability in the policies and practices of post-secondary institutions. This paper reviews what comparative empirical research has been undertaken on sustainability in post-secondary education (PSE) within eight leading international journals publishing on sustainability and education. Three predominant themes of research on the topic are identified within the review: research comparing sustainability curricula across institutions (both within specific disciplines of study and across disciplines); research comparing campus operations policies and practice across multiple institutions; and research on how to best measure or audit approaches and outputs in sustainability in PSE. This review of the research literature supports the contention within the literature on sustainability in PSE that most research on the topic is focused on case studies rather than comparison of multiple institutions. The comparative research that is emerging from the field is concentrated on assessing measurable outputs for environmental externalities within institutional operations, with little examination of sustainability uptake and outcomes across broader institutional policies and practices.