Public and professional concern associated with the idea of genetic screening has generated numerous publications on the ethics of genetic screening (e.g. 1-4). Concerns revolve around inadequate consultation before screening is carried out, the unearthing of worrying risks, the use of genetic information in ways that could be disadvantageous to the person involved, stigma, and a phenomenon known as the 'technological imperative', which means that simply because a technology is available there is a tendency to use it. Most reports agree that, in practice, the main ethical problems are likely to involve screening for risk of common diseases of adult life, because of the possible impact on a person's healthy self-image, implications for health and life insurance, and the possibility of commercial exploitation of people who know themselves to be vulnerable. In this paper I do not propose to address these issues directly. I have been invited to discuss this subject as a clinician involved with genetic screening, counselling and prenatal diagnosis for the haemoglobin disorders, the most common serious human recessively inherited diseases. Since we are scientists, any recommendations we make should be based on experience: my aim is to show that experience is often surprising, and that it is often possible to meet public concerns by taking quite simple practical steps.