In several sub-Saharan African countries, HIV has spread widely via heterosexual sex, infecting 5% or more of adults. No Asian country has an epidemic that has made similar headway in heterosexuals, although the virus has spread widely in key affected populations like men who have sex with men, injecting drug users, and sex workers. Papua New Guinea, however, is distinct from other Asian countries in many ways, and 10 years ago, it appeared that HIV was set to explode there in the heterosexual population. This sub-Saharan–like epidemic never came to be, and the country now is struggling to realign its response. The central challenge today is conducting appropriate surveillance to accurately describe the epidemic the country does have, which is easier said than done given that the virus has spread in often remote, geographically distinct areas and in key affected populations that are difficult to reach for social reasons.