The conventional perspective that fear is a bad motivator for behavioral change, so critical to public health, is both an empirical observation and a moral judgment. This chapter challenges the belief that fear cannot work and is, indeed, counterproductive. The chapter then turns to the ethical debate, which for years was shaped by bioethics. The chapter concludes by arguing that the perspective of bioethics, so centrally concerned with the individual, provides an inadequate moral frame for thinking about fear-based campaigns. Instead, the chapter proposes the notion of public health ethics, which has as its grounding principle the enhancement of population well-being. Fear-based campaigns may be morally legitimate once the population benefits are clearly articulated and the potential social costs carefully evaluated in a process that is open, transparent, and engages the populations toward whom fear-based campaigns will be directed.