Purpose: The integration of sustainability is more matured in the corporate sector. However, the topic received less attention in higher education institutions (HEIs). Therefore, this study aims to conceptualize an integration framework and proposes sustainability integration and implementation index in the HEIs. Design/methodology/approach: The index was developed from previous literature. For the implementation of the index, three universities were selected. The required data collected from websites, internal documents and interviews with the high officials of these universities. Findings: Sample universities have somehow inclination toward the broad agenda of sustainable development, but still, they lack integration, implementation and reporting of their sustainable practices. Moreover, the departments have positive and practical intent toward sustainability especially regarding the environment, designing curriculum, teaching, research activities and volunteerism. However, in assessment, the social and economic contributions of these universities revealed to be somewhat mild. The findings also evidenced heterogeneity among the sample institutions to follow the said agenda which reflects a lack of awareness and policy or a centralized or regulatory push from the top. Research limitations/implications: The study is limited to three universities in Khyber Pakhtunkhwa, Pakistan. Hence, in the future, the framework and index may be tested in other universities of the country or region. Nevertheless, the study carries theoretical significance in the literature of sustainability. Practical implications: The study has practical implications for academia, regulatory bodies and universities to integrate, implement and report sustainability in HEIs. Originality/value: The study proposes and validates the sustainability integration and implementation index in HEIs. The index is unique and has originality or value particularly for HEIs of the developing countries.