The remarkable progress in genetics over the last 50 years has led to the development of genetic technologies to identify or alter genes in living organisms, and these technologies can be applied to people. This article presents background information on the role of genetics in human disease, outlines the technologies, and discusses the sources of the strong push for a genetic approach to ill-health and some implications and harmful consequences of using these genetic technologies. The determinants of most diseases are complex and are embedded in a social context. To focus on only one strand of this web--the genetic strand--because it is one that may be amenable to biological/pharmaceutical treatment, although profitable for industry, does not address other important determinants of health and may lead to a harmful overemphasis on genetic approaches. The author outlines some limitations to the potential contribution of genetic technologies to population health across the globe and the need for policy development if these technologies are to have an appropriate place in health care.