In this paper, we discuss the complex relationship between health technology assessment (HTA) and the regulation of medical devices and procedures. The relationship is first examined through a conceptual framework describing the itinerary from research to three levels of policy making: micro (standards of medical practice), meso (institutional rules), and macro (health policies). Four reports from the Quebec Health Technology Assessment Council (CÉTS) are used to illustrate how HTA activities can influence the regulatory mechanisms operating at each decision-making level. We then discuss the skillful balancing act required from HTA agencies to constantly negotiate the right distance from the regulatory process at which to operate. We propose that HTA agencies should not be incorporated into any regulatory, auditing, or monitoring process. Finally, the relationship between health technology assessment and health care reform is discussed. It is suggested that HTA activities will contribute most during the data-driven preparation and consolidation phases of a reform process. The fast pace of events and the political turmoil characteristic of the implementation phase provide a less receptive environment for HTA contributions.