This study investigates voluntary sustainability reporting by U.S. universities. Using a structural equation modeling approach and Poisson regression, this analysis explores the relevant motivations for and obstacles in disclosing sustainability information through the Sustainability Tracking, Assessment & Rating System. The preparation of sustainability reports on a voluntarily basis involves significant financial costs for universities that typically grapple with tight budgets. However, universities may want to inform their stakeholders about relevant developments at the university. The results show that the fulfillment of societal expectations is one of the most relevant motivations, whereas a lack of reporting-related organizational structures represents the most important obstacle. The study provides important theoretical and practical contributions to the literature, including scales that measure the level of motivations and obstacles to reporting sustainability information. Furthermore, the findings can improve universities’ sustainability reporting and assessment frameworks.