The increasing availability of health care technology--boosted by considerable advances in areas like biotechnology, biomaterials, surgical techniques and computer technology--has accompanied burgeoning health care costs, and for this reason an increasing number of subjects (clinicians, health product makers, regulators, patients, hospitals, managers, payers, government leaders) demand for well-founded information to support decisions about development, adoption, acquisition and use of new and existing technologies. Technology assessment is a form of policy research that identifies policy issues, assesses the impact of alternative courses of action, and presents findings. This article is aimed at describing the historical development, reviewing the various definition and classifications, illustrating the purposes Fnd actors of Health Technology Assessment and its possible applications in the current healthcare scenario.