The field of health technology assessment (HTA) is still relatively new, but it has shown remarkable growth over the last decade, having spread first from the United States to Europe, and now to the entire world. HTA seeks to couple evidence with decision-making, and thus has similarities to evidence-based health care and evidence-based policy-making. The early history of HTA, beginning around 1975, reveals a first period of synthesising available evidence-principally that dealing with efficacy and cost-effectiveness of health care interventions-so as to put it in a format helpful to health policy-makers, especially those in national governments. From 1985 or so, the focus of the second period was on seeking more effective links with these policy-makers, particularly in Europe. The most recent period, beginning in the late 1990s, has been increasingly devoted to more effective dissemination and implementation in order to influence administrators and clinicians. While early assessments tended to focus on large, expensive, machine-based technologies, the scope has gradually widened to include smaller technologies, 'softer' technologies (such as counselling), and health care needs. Actual assessments have also taken on broader issues, such as organisational, social, and ethical implications. In the Member States of the European Union (EU), HTA activities are increasingly visible, and almost all now have a national focus for HTA associated with the Ministry of Health or its equivalent. Central and Eastern European countries are also developing HTA activities. Most recently, HTA has been highlighted by health policy documents from the European Commission. It seems likely that HTA will in the future be institutionalised in some form as part of EU activities.