This book grew out of our sense that the World Trade Organization (WTO) regime on government procurement – currently consisting principally of the plurilateral Agreement on Government Procurement (GPA) – is undergoing a far-reaching transition from constituting an important but relatively obscure element of the WTO to becoming a cornerstone of the international trading system. This change is occurring first and foremost as a result of the pending accession to the Agreement of important developing and transition economies such as China, Jordan and Armenia but also as a result of the ongoing effort to modernize the Agreement which is nearing completion and of increased interest in government procurement as a dimension of world trade in light of the recent economic crisis. There is, in our view, a critical need for informed discussion and reflection on these developments in the international community and among international legal scholars, practitioners and students. There is, of course, already a significant body of literature on the GPA as it emerged from the Uruguay Round and on other aspects of the WTO's procurement work, in particular on transparency, and we do not seek to replicate this here. Rather, the aim of the present volume is to explain, and to explore, the most recent developments concerning the WTO regime for government procurement, and to stimulate debate on the challenges that they pose.