A range of regulatory approaches are being applied to e-cigarettes globally. This chapter examines the reasons for this and what this means for broader tobacco control efforts. The chapter starts with a discussion of tobacco control and how evidence has influenced the development of international tobacco control policies. The chapter then explores the development and emergence of e-cigarettes. It identifies and discusses the arguments and evidence used in the e-cigarette regulatory debates. The chapter concludes by suggesting that research in this domain could improve our understanding of what factors influence the regulatory environment, thus why different regulatory approaches as pursued.