The role of higher education institutions in promoting environmental sustainability is not limited to research activities but also covers improving their campus infrastructure into a more environment-friendly setting as well as updating their curricula to include courses on environment and sustainability. The contemporary concept of ‘green university’ has been embraced by an increasing number of universities and attracted attention from scholars all over the world. The current study aims to contribute to the recent research stream on green universities by disclosing the relationship between academic performances of the universities and ‘being green’. For this purpose, the current research tests (i) whether sustainability relates to the academic performances of universities, (ii) whether the relationship (if it exists) is valid when the academic scores are aggregated to a composite score, (iii) whether the relationship (if it exists) is contingent upon the scores of environmental performance at the country level and (iv) whether the relationship (if it exists) holds for out-of-sample estimations. Utilizing the sustainability scores of the universities published by UI GreenMetric and four major academic ranking systems, the findings of the current research support the earlier discussions on the importance of the environmental sustainability policies implemented by university managements. The results reveal that being green has a reflection on the university rankings, and the environmental sustainability can serve as a competitive advantage for the world universities.