The Western Pacific Region, the most populous of six regional groupings of World Health Organization (WHO) member states, has seen the emergence of a series of novel zoonotic infections in the last decade. This has focused attention on addressing underlying risks and vulnerabilities in the complex interactions among people, animals, and environments as a better way to counter emerging diseases. This "One Health" approach is pertinent to the region because, it is a "hot spot" for the emergence of novel diseases from wildlife, because unexpected epidemics of re-emerging zoonotic diseases have caused morbidity and mortality in urban and periurban communities, and because it remains a sanctuary for well-known zoonotic infections. In this chapter, selected regional, multicountry, and national steps to operationalize One Health are discussed. While the region is well positioned to exploit the opportunities that have come with outbreaks of new diseases, the array of disconnected and overlapping initiatives from various consortia, donors, research institutes, and UN agencies is to some extent impeding the development of better ways of managing both new and old infections for the local, regional, and global good.