Background. The purpose of this study was to determine if the Healthier People Health Risk Appraisal and the RiskPlan Report, two different methods for measuring health risks of an employee population, produce the same estimates of health risk prevalence. Methods. The prevalence of each of seven risk factors, directly measured by the Healthier People Health Risk Appraisal and predicted by the RiskPlan Report using demographic and normative data, were compared for a group of 239 employees participating in a voluntary health screening. Further, the 239 participants and 426 nonparticipants were compared with respect to demographic factors gleaned from personnel records, and risk factor prevalence derived from the RiskPlan Report. Results. Significant differences were found in the prevalence of six of the seven risk factors measured by the Healthier People Health Risk Appraisal and predicted by the RiskPlan Report. Also, risk factor prevalence predicted by the RiskPlan Report was not significantly different in the participants and nonparticipants although three critical sociodemographic variables were significantly different. Discussion. The results suggest that the prevalence of health risks based on normative data and the demographic profile of a population are not similar to those directly measured, and some doubt is raised about predicting health risks based on these data.