This paper presents the results of the first comprehensive international survey to catalogue health technology assessment (HTA) activities. By 1995, there were formal HTA programs in 24 countries established mostly in the late 1980s and early 1990s. European countries generally have one or two federal or provincial HTA programs each, Canada has an extensive network of federal and regional organizations coordinated by a central body and the US has 53 HTA organizations, the vast majority of which are in the private sector. While the commitment of the US government to HTA has been erratic, the private sector has been witness to an expansion of HTA activities by insurance companies, hospitals, medical/device manufacturers, consulting firms and health professional societies. In contrast to other developed countries, the current state of technology assessment in the US is decentralized, fragmented and duplicative. We conclude by discussing the importance of a US HTA agency at the national level.