3ie promotes evidence-informed, equitable, inclusive, and sustainable development. They support the generation and effective use of high-quality evidence to inform decision-making and improve the lives of people living in poverty in low and middle-income countries. They provide guidance and support to produce, synthesise and quality assure evidence of what works, for whom, how, why and at what cost.

Since its founding in 2008, 3ie has awarded over 300 grants (243 impact evaluations, 38 systematic reviews and 23 other studies) in over 50 countries, with a total value of US$104,328,729. 

3ie has offices in New Delhi, London, and Washington, DC. The three main funders of 3ie are the Bill & Melinda Gates Foundation, UKaid through the Department for International Development, and the William and Flora Hewlett Foundation.