Discovering Human Sexuality is an evidence-based, accessible introduction to the study of sexuality and the diverse ways in which it brings joys and challenges to our lives. The backgrounds of the authors-in biology, sociology, teaching, and writing-have made possible a text that is multidisciplinary, authoritative, sex-positive, and a delight to read. Now in its Third Edition, Discovering Human Sexuality has established itself as a popular and widely praised text that respects diversity both in the sexual world and among the students who read it. The Third Edition maintains the overall presentation of its predecessors, but adds coverage of recent sex-related developments in research, medicine, law, politics, and social trends. In addition, the authors have included two substantial appendices: one looks at sex and sexuality from an evolutionary perspective; the other provides additional material regarding the role of the nervous system in sexual functioning. The two appendices have been developed from sections of the authors’ other text, Human Sexuality. The intent is to provide options for more advanced learning while leaving the main text accessible to students with more limited backgrounds in biology. The Third Edition has many new boxes, illustrations, FAQs, and other features, as well as countless new references. What shines through is the richness of ideas about human sexuality that only an interdisciplinary collaboration can provide.