Conservation medicine is an emerging discipline, focussing on the intersection of ecosystem health, animal health, and human health. Work in the biomedical and veterinary sciences is now being folded into conservation biology; to explore the connections between animal and human health; trace the environmental sources of pathogens and pollutants; develop an understanding of the ecological causes of changes in human and animal health; and understand the consequences of diseases to populations and ecological communities. Conservation Medicine defines this new discipline. It examines ecological health issues from various standpoints, including the emergence and resurgence of infectious disease agents; the increasing impacts of toxic chemicals and hazardous substances; and the health implications of habitat fragmentation and degradation and loss of biodiversity. It will provide a framework to examine the connections between the health of the planet and the health of all species and challenge practitioners and students in the health sciences and natural sciences to think about new, collaborative ways to address ecological health concerns.