Antiretroviral therapy (ART) is difficult in poor settings. In 2001, the Thai government adopted the policy to scale-up its treatment initiative to meet the needs of all its people. Employing qualitative approaches, including in-depth interviews, document review and direct observation, this study examines the processes by which the universal ART policy developed between 2001 and 2007, with the focus on the connections between actors who shared common interests--so-called policy networks. Research findings illustrate the crucial contributions of non-state networks in the policy process. The supportive roles of public-civic networks could be observed at every policy stage, and at different levels of the health sector. Although this particular health policy may be unique in case and setting, it does suggest clearly that while the state dominated the policy process initially, non-state actors played extremely important roles. Their contribution was not simply at agenda-setting stages--for example by lobbying government--but in the actual development and implementation of health policy. Further it illustrates that these processes were dynamic, took place over long periods and were not limited to national borders, but extended beyond, to include global actors and processes.