The dramatic increase in environmental changes and developmental challenges has raised concerns that appear on all social and political agenda. All these challenges and their interactions highlight an urgent need to detect unexpected changes and have more reliable and comprehensive information to reflect improvement or deterioration of the state of the environment. In this regard, explore adequate measures of progress and monitoring towards sustainable development have taken on a new urgency and ‘keeping the global environment under review,’ launched by the United Nations General Assembly (UNGA) in 1972. Since sustainable development is a dynamic process of changes among economic development, environmental quality and social equity it requires an integrated decision-making process in consistent with future as well as present needs. Therefore, the United Nations Commission on Sustainable Development (UNCSD) in 1992 which designed to holistically address the three ‘pillars’ of sustainable development also called for the identification of concrete policy measures and international cooperation for providing information for decision-making. Indeed disclosing information, publishing data and measuring process in order to identify whether policies has been effective assist policymakers to move toward global agreed targets. In particular, policymakers demand for standardised and easily understandable information to make sustainable and appropriate decisions among competing policy options. The crucial need to have more accurate data and capture a picture of progress generated indicators and indices as a necessary pre-requisite tool for governance. Indicators and indices by simplify and quantify information of complex issues facilitate communication with decision-makers and the public. Indeed, they provide valuable information for monitoring and enable to make some rough estimates of the state of environment. In this regard, the efforts to develop indicators and indices, as a science and policy tool, have been increased to measure progress towards sustainable development. These initiatives are important and practical steps to better inform governments and societies about the state of the environment and move towards a sustainable future. In the realm of international environmental law, like other disciplines, developing core sets of consistent and relevant indicators have been explored to track environmental performance and determine whether countries are complying with their legal obligations. However, based on the field and subject there is various range of indicators and indices. Therefore different technical definitions and framework is generated in the various disciplines. On the other hand, inadequacies in the available data, lack of basic statistical information on the environment and also insufficient policy indicators can lead to misinterpretation for policymakers. Therefore, a standardised process involving an integrated approach is required in order to develop measurable indicators and indices and to avoid ambiguity. This paper is a preliminary investigation into the policy indicators and indices, their current trends and challenges to examine their important role and how standardised indicators and indices could facilitate implementation of, and improved compliance with, international environmental agreements.