This is the introductory chapter of the book, which provides a review of the science in key areas of the relationship between environmental contaminants and reproductive and developmental health for students and practitioners in the fields of public health, environmental health and research, and medical and allied health professional training. Environmental reproductive health focuses on exposures to environmental contaminants, and their potential effects on all aspects of future reproductive health throughout the life course, including conception, fertility, pregnancy, child and adolescent development, and adult health. The book focuses on the role of/implications for/potential effects of exposure to endocrine-disrupting chemicals (EDCs) and subsequent reproductive and developmental outcomes. It brings together the core environmental health sciences that form a foundation of information from which to join with other disciplines and partners in related health, social, community, legal, and policy fields to explain the relationship between environmental contaminants and reproductive and developmental health.