Advances in medical technology such as those linked to the human genome project are increasing the potential for predictive testing for a wide range of health threats. There have not been comparable advances in understanding of the psychological factors involved in such testing. These factors and issues relating to them are examined, and it is suggested that a cognitive-behavioral approach to the understanding and management of adverse reactions to testing is likely to be particularly fruitful. The use of such an approach should result in the development of effective pre- and posttest interventions to prevent, minimize, and manage distress associated with screening.