Research aimed at identifying genes contributing to the aetiology of psychological disorders is in progress. This raises the possibility that genetic testing for such genes might become available. In this paper the possible psychological consequences of genetic testing for psychological disorders are examined. It is proposed that genetic testing may cause psychological and behavioural reactions that actually increase the person’s risk of developing a psychological disorder or may maintain existing problems. It is also suggested that cognitive-behavioural models may be able to aid prediction of some of the likely consequences of testing and identify people who are likely to react in particularly negative ways to news of their genetic risk. If genetic tests for psychological disorders are developed, it is important that research is carried out into the psychological and behavioural effects of testing and ways of minimizing adverse effects, before such tests become widely available.