South Asia, a region of strategic importance, faces public health challenges on a demographic and geographic scale unmatched in the world. India, Pakistan, Bangladesh, Nepal, and Sri Lanka are home to nearly one-fifth of the world’s population.  Even more dramatic, however, these countries are home to two-thirds of the world’s population living on less than $1 a day. South Asia’s low life expectancy and high rates of malnutrition, infant mortality, and incidence of TB and HIV/AIDS are second only to those of sub-Saharan Africa. The region faces not only these and related health problems—poor sanitation, poor maternal health, poor access to healthcare services, and widespread malaria—but also an emerging chronic disease epidemic. Despite the magnitude of these interrelated challenges, these five countries on average spend less than 3.2 percent of their gross domestic products on health, compared to a global average of 8.2 percent. They constitute the world’s only region to see its health expenditures fall from 2000 to 2006.