Laws protecting against unfair competition are well established in some European countries, but not well considered in other countries, notably not in jurisdictions of Anglo-American legal tradition. This essay explores the historical roots of unfair competition law in the Paris Convention for the Protection of Industrial Property of 1883 and the paradigmatic shift national unfair competition laws have undergone due to the movement of consumer protection and the ongoing harmonization of laws in the EU. It examines the very concept of fairness, in particular as it may or may not apply to unethical advertising, as well as the interfaces between unfair competition law, the protection of intellectual property, contract law and antitrust law. The contribution also discusses the many different ways of enforcing unfair competition law and the problems of over- or under-enforcement. It concludes by affirming the need for protecting both consumers and competitors against unfair business practices on the one hand, and, on the other, the persistent task of developing a systematically consistent and stringent general framework for all rules on unfair competition.