Background/Context: PISA has catapulted the OECD- an organization whose mission is the global growth of market economies-to a central role in international education policy making, rivaling and sometimes outdoing the various national governments in influence. While claiming scientific evidence as the basis for the accountability regime it promotes, the policy frameworks and principles it has adopted over the past two decades are rooted in ideas about the superiority of market mechanisms that are contested in many member nations. Yet, while exerting strong influence on national educational practices in pursuit of a narrow and contested policy agenda, it is not easily influenced through established democratic processes. Purpose: In this paper, I discuss key OECD ideological and policy shifts that form the background for PISA. Secondly, I focus on the OECD's governance mechanisms and the obstacles it presents to public scrutiny. Research Design: Drawing on recent scholarship on the power of transnational policy networks to influence national policy through the soft power of epistemic communities, this paper analyzes policy documents and relevant research from OECD and PISA to identify ideological commitments and configurations of power that form the backdrop for PISA. Conclusion: I propose that in a world of global policy making, the influence of organizations like the OECD highlights deficits in the constitution of the global democratic public sphere that would foster the accountability of these organizations.