Health risk appraisals (HRA) are being used increasingly by health centers and worksites to inform people of their personal mortality and morbidity risks. However, recent research suggests that many HRAs have limited reliability and validity with respect to coronary heart disease, the leading cause of death in this country. Self-scored HRAs appear to be considerably less accurate in predicting CHD risk than computerized instruments, chiefly because people do not always know the physiologic values required by these instruments and because they frequently make errors computing their scores.