Dr. Calvin Schwabe's vision of "One Medicine" has long inspired many in the public health community to strive toward bringing human and veterinary medicine together to improve the public's health and well-being around the world. In an increasingly human-dominated world, as Dr. Schwabe suggested many years ago, human health provides the most-logical unifying or apical cause in veterinary medicine's hierarchy of values. Veterinarians in all aspects of the profession-have opportunity and responsibility to protect the health and well-being of people in all that they do, including protecting food security and safety; addressing threats to antibiotic sensitivity; preventing and controlling zoonotic emerging infectious diseases; protecting environments and ecosystems; participating in bio- and agro-terrorism preparedness and response; using their skills to confront non-zoonotic diseases (such as malaria, HIV/AIDS, vaccine preventable diseases, chronic diseases and injuries); strengthening the public-health infrastructure; and advancing medical science through research. This article provides an overview of contributions made by veterinarians in each of these areas, and discusses the challenges to be overcome and the need for strategic thinking and action to achieve the vision of "one medicine".