Since the 1990s over 158 countries established pro-market reforms in telecommunications-a fast pace for such a drastic change. For example, Sweden and Botswana, two nations vastly different across multiple dimensions, both liberalized their telecom sectors. Why did so many countries adopt liberal reforms in such a short period of time? Conventional wisdom highlights the role of global markets and technology, powerful states, global diffusion, and domestic politics. I argue that contrary to these claims, diffusion through key international organizations is the critical and overlooked factor in explaining rapid global convergence of pro-market telecom reforms. Using an original dataset for 189 countries between 1970 and 2003 and event history analysis, I demonstrate that membership in key liberal trading organizations, especially the WTO and the OECD, increases the likelihood that countries will adopt liberal pro-market reforms in telecommunications. These results speak directly to current public policy debates about the reregulation of global markets and bridges the literatures of policy diffusion, institutional design, and regulatory regimes.