Geneticization is a broad term referring to several related processes such as a spreading tendency to use a genetic model of disease explanation, a growing influence of genetics in medical practice, and the slow changing of individual and societal attitudes towards reproduction, prevention and control of disease. These processes can be demonstrated in medical literature on preventive genetic screening and counselling programs for beta-thalassaemia in Cyprus, the United Kingdom and Canada. The preventive possibilities of the new genetic and diagnostic technologies have been quickly understood and advocated by health professionals, and their educational strategies have created a web of social control, in marked contrast to the alleged voluntary decision-making process and free choice. Genetic diagnostic technologies have led to considerable changes in control and management of beta-thalassaemia, and have generated a number of unresolved incongruities.