Objective: Health technology assessment (HTA) can be used both to promote access to safe, efficacious, and cost-effective technologies, and to discourage access to undesirable ones. Yet HTA has had less success than might be hoped in pursuing the latter goal. This paper examines the scope of HTA as currently practiced to contribute to regulation of access to undesirable technologies.Design: The study design is a critical analysis of HTA's methods, based on an exposition of the normative issues involved in restriction of access to health technologies. The paper classifies technologies that might figure as potential candidates for exclusion into five categories and underscores the key social and ethical dilemmas associated with limiting their use.Results: For four of the five categories of technology outlined, limitation of access necessarily involves denial of benefit. Limitation of access thus inevitably raises difficult normative issues. We show that these are ill-addressed by the range of “evidence” typically considered in technology assessments, which centers predominantly on clinical and technical features such as efficacy, safety, and costs.Conclusions: If HTA is to enhance our ability to make reasonable decisions concerning the use and diffusion of health technologies, it must better integrate consideration of the social, political, and ethical dimensions of health technologies into the process of technology assessment. We suggest a framework within which to approach this goal.