The quality and design of infrastructure play a key role in shaping how we live, what we do, and how we interact in almost every aspect of life. It determines economic structures and outcomes, social systems, personal well-being, and environmental impact, as well as development pathways. Policy makers are increasingly aware of the contribution environmental, social and governance (ESG) and broader sustainability factors make in ensuring quality infrastructure investment. As institutional investors gain exposure to infrastructure through their portfolio investments, there is increasing recognition that ESG factors are relevant for their infrastructure investments. However, there are challenges in implementation, due in part to the particularities of infrastructure markets. This chapter analyses the growing use of ESG criteria in institutional investment in infrastructure, including investor motivations and objectives, as well as ESG frameworks and tools and related implementation issues. It concludes by offering options for the way forward.