Emerging infections, many zoonotic, are caused by a variety of pathogens with global distribution. Previously rare pathogens have emerged; global travel facilitates their rapid spread. Human encroachment on remote areas has brought contact with zoonotic diseases never before characterized. Although systematic study of rare outbreaks can be challenging, knowledge of emerging pathogens and their effects on women is accumulating. This article discusses effects of lymphocytic choriomeningitis virus, West Nile virus, severe acute respiratory syndrome coronavirus, avian influenza A virus, viral hemorrhagic fevers, spirochetal illnesses, and Chagas' disease. The potential impact of candidate bioterror agents and issues of prophylaxis and therapy are discussed.