The new genetics promises a new kind of public health practice in which the health of populations is defined by freedom from risk of genetic disease. This paper critically examines a number of assumptions underlying the genetic conception of health and discusses some likely implications of the increasing use of the technologies of genetic screening and genetic counselling in the fulfilment of public health objectives. It examines concepts of the body, the self and society underlying the search for genetic-based disease, and it unpacks the rhetoric of the ‘right to know’ and ‘informed choice’ which characterizes the discourse of the new genetics. The paper also explores some implications of the focus on ‘the family’ in genetic counselling, drawing particular attention to new inter-personal responsibilities and obligations implied by the need to know about the genetic health of one's family members and future offspring. The paper concludes by stressing the need for a thoroughgoing appraisal of the impact of the new genetics on public health practice.