Background: There has been tremendous scale-up of antiretroviral therapy (ART) services in the Asia Pacific region, which is home to an estimated 4.7 million persons living with HIV/AIDS. We examined treatment scale-up, ART program practices, and clinical outcome data in the nine low-and-middle-income countries that share over 95% of the HIV burden in the region. Methods: Standardized indicators for ART scale-up and treatment outcomes were examined for Cambodia, China, India, Indonesia, Myanmar, Nepal, Papua New Guinea, Thailand, and Vietnam using data submitted by each country to the WHO/ The Joint United Nations Programme on HIV/AIDS (UNAIDS)/UNICEF joint framework tool for monitoring the health sector response to HIV/AIDS. Data on ART program practices were abstracted from National HIV Treatment Guidelines for each country. Results: At the end of 2009, over 700 000 HIV-infected persons were receiving ART in the nine focus countries. Treatment coverage varies widely in the region, ranging from 16 to 93%. All nine countries employ a public health approach to ART services and provide a standardized first-line nonnucleoside reverse transcriptase inhibitor-based regimen. Among patients initiated on first-line ART in these countries, 65–88% remain alive and on treatment 12 months later. Over 50% of mortality occurs in the first 6 months of therapy, and losses to follow-up range from 8 to 16% at 2 years. Conclusion: Impressive ART scale-up efforts in the region have resulted in significant improvements in survival among persons receiving therapy. Continued funding support and political commitment will be essential for further expansion of public sector ART services to those in need. To improve treatment outcomes, national programs should focus on earlier identification of persons requiring ART, decentralization of ART services, and the development of stronger healthcare systems to support the provision of a continuum of HIV care....Keywords: antiretroviral therapy, Asia Pacific, HIV, outcomes, scale-up, treatment