The Equator Principles (EPs) are codes of conduct for project finance on the sustainability impacts of a project and on the risk assessment procedures of financial institutions that have adopted the principles — Equator Principles Financial Institutions (EPFIs). The EPs were launched 10 years ago and have undergone three revisions, while the EPFIs have increased from 10 to 78 members in 2013. This paper correlates these 10 years of existence to the adolescent stage of the EPs, still seeking to establish relevance. Environmental and social assessment of projects is increasing in global adoption and scope and the EPs strive to redefine these assessment practices. Critics reason, however, that without implementation efforts and enforcement, the EPs are merely window dressing and will not contribute to any change to sustainable development. The authors point out gaps in how EPFIs address the implementation of guidelines in project finance decision making, how projects implement environmental and social assessment processes in practice and whether the implementation will have a positive effect on project sustainability. The paper concludes that these gaps need further research and analysis to better understand the role of the EPs in sustainable development.