The ASEAN region is an important environment and health hotspot due to increasing pollution, vulnerability to climate change, infectious disease risk, and increasing risk of Non-communicable Diseases (NCDs). The Manila Declaration on Health and Environment from the Asia-Pacific Regional Forum on Health and Environment in 2016 requested UN agencies to support promotion of environment and health impact assessment as one of the tools for achieving more sustainable and equitable development, including valuation of economic costs of health and environmental impacts due to pollution. In light of the above commitment and requests, the UNDA project, Using Environmental Health Data and Tools to Advance the Sustainable Development Goals (SDGs) in the ASEAN Region, will enhance the capacities in the region to develop and implement policies to reduce environmental risk factors to human health and improve health in the urban environment as contributions to build back better from the COVID-19. It will demonstrate environment and health co-benefit and cost of inaction in Indonesia, Lao PDR and Thailand while paying attention to vulnerable, less advantaged groups such as young children and the poor. Good practices will be disseminated across ASEAN Member States to achieve the Project’s Expected Outcomes: 1) Policies to address priority environment and health risks developed in selected ASEAN countries by utilizing knowledge on co-benefit and cost of inaction, and 2) ASEAN leaders apply the knowledge on integrated environment and health policy approaches to set national priorities in achieving SDGs and to recognize air pollution as NCD cause. Thematically, the project will focus to reduce the adverse per capita environmental impact of cities including air pollution by paying special attention to sustainable urban design principles that promote healthy lifestyles, integrated management of municipal and other wastes as well as vector-borne diseases such as dengue and malaria. It will also and encourage national effort to strengthen environment and health response to prevent the next pandemic and to build back better. This UNDA project will be implemented by the United Nations Environment Programme (UNEP) as part of Subprogramme on Chemicals, Waste and Air quality and in coordination with other UN agencies and the ASEAN Secretariat. It is aligned with the ASEAN-UN Environment and Climate Change Action Plan (2016-2020).