This article addresses the issue of the development of national science policies in OECD countries in the 1960s. It argues that the Organisation for Economic and Co-operation and Development (OECD) acted as a policy innovator playing a central role in the development and adoption of what we call the "OECD model of science policy-making". Through a detailed analysis of the OECD country reviews, we reveal the OECD model and its seven key functions: horizontal coordination and advice, planning and budgeting, priority-setting, resources allocation and administration. Through analysis of OECD archives, we extract the reasons why OECD changed its role and the absence of a reference point against which to benchmark national situations. It highlights the ways the pre-existing mode of operation of OECD, centred on country reviews and peer pressure, was modified, and how effective these changes have been in the diffusion of the model among OECD members.