Established guidance for the protection of human subjects in research has provided the framework for research and clinical practice in genetics. Three key principles to emerge are the requirements for consent, privacy and confidentiality. However, recent research on genetic susceptibility to common diseases indicates that it may be more difficult to decide if and when genetic testing will be appropriate. Risks of disease may be low and interventions may not be available. Today, debate is primarily focussed on ethical issues raised by the use and storage of genetic information. One of the earliest experiences of genetic testing for some people is likely to be in the area of pharmacogenetics. Debate about ethical issues has been focused on the implications of patient stratification, particularly with regard to the availability of medicines for small groups and the significance of racial variation in response to medicines. The possible use of personal genetic information by insurance companies and employers has also been an issue that legislators have taken seriously.