This paper conducts a comprehensive analysis of the sustainability assessment of Higher Education Institutions (HEIs) using the Times Higher Education Impact Ranking (THEIR), focusing on the top 25 institutions in 2022. Through qualitative and quantitative content analysis, the study critically examines THEIR’s methodology, key performance indicators (KPIs), motivations, and gaps. Results indicate a significant concentration of top-performing HEIs in developed regions, mainly Europe, North America, and Oceania, with the United Kingdom leading in overall performance. However, disparities in sustainability-related knowledge production are evident, as HEIs from developing regions, especially Latin America and Africa, are underrepresented. The analysis also reveals varying scores and limited variability in specific Sustainable Development Goals (SDGs), emphasising the need for continuous efforts to enhance sustainability dimensions. Despite the strengths of THEIR, such as a transparent methodology and comprehensive approach, the study acknowledges limitations, including reliance on self-reported data and a focus on research-intensive institutions. In conclusion, while THEIR offer valuable benchmarking data for HEIs comparisons and improvements, addressing disparities and refining indicators can enhance the tool’s accuracy and inclusivity in assessing sustainability in higher education.