This chapter presents an assessment of illicit trade in counterfeit medicines, which in the 21st century has changed starkly in its geographical scope and pervasiveness across different product classes. Masquerading as curative medicines, counterfeit pharmaceuticals are increasingly prevalent and profitable. In addressing the threat of counterfeit drugs, there is obvious scope for benefiting both consumers and international pharmaceutical firms. Pharmaceutical counterfeiting has been identified over thirty years ago but went undiscussed. The industry now not only readily concedes counterfeiting is a threat to its business, in some cases it publicly addresses the strategies and anti-counterfeiting technologies in use and development. Acknowledging the problem enables better partnering with governments, health advocates and other supply-chain entities, since the incentives are aligned to prevent counterfeiting. In light of the more public and more aggressive campaigns against counterfeiting, it is important to examine the extent of the problem, what is known about counterfeit production and distribution, the links to organised crime and the policy responses that have been particularly effective. This paper reviews each of these in turn, as well as new policy initiatives that appear promising.