In this article we undertake some conceptual clarification of the concepts of biopower and biopolitics, and argue for their utility in contemporary analysis. We consider Foucault's development of these concepts, and differentiate his view, which is close to ours, from the philosophical take-up of the terms by Giorgio Agamben and Antonio Negri. Biopower, we suggest, entails one or more truth discourses about the ‘vital’ character of living human beings; an array of authorities considered competent to speak that truth; strategies for intervention upon collective existence in the name of life and health; and modes of subjectification, in which individuals work on themselves in the name of individual or collective life or health. We argue that, while exceptional forms of biopower, especially in conditions of absolutist dictatorship, and when combined with certain technical resources, can lead to a murderous ‘thanatopolitics’—a politics of death—biopower in contemporary states takes a different form. It characteristically entails a relation between ‘letting die’ (laissez mourir) and making live (faire vivre)—that is to say strategies for the governing of life. Using examples from our own current research, we consider recent developments in biopower around three themes: race, population and reproduction, and genomic medicine.