The OECD Survey on Blended Finance Funds and Facilities represents a major step forward to consolidate evidence and provide further policy guidance in support of the OECD DAC Blended Finance Principles, whose focus is unlocking commercial finance for the Sustainable Development Goals. This working paper presents findings from the 2018 survey edition relating to the management, capital structure, investment strategy and portfolio allocation of the surveyed blended finance funds and facilities. The quantitative analysis is complemented by the OECD statistics on private finance mobilised by official development interventions and by information provided by Convergence. It will be followed by another OECD Development Co-operation working paper discussing the development strategy, performance tracking and evaluation approach. The 180 responses received illustrate to what extent blended finance funds and facilities vary widely in characteristics and functioning. Collectively, the managing organisations reported over USD 60.2 billion invested in 111 developing countries at the end of 2017. This new evidence confirms trends observed on the broader blended finance market (priority sectors, geographical coverage, targeted SDGs), while shedding light on additional aspects (e.g. investors, clients and investment instruments).