In brief:High-risk, physically demanding occupations such as police work are associated with high medical costs. The potential economic benefits of health assessment, disease prevention, and performance testing Programs, in contrast to post hoc remedial Programs, have seldom been evaluated. This article presents the effects of such a program on 4,480 California Highway Patrol officers who were tested every six months over an 18month period. Mean systolic blood pressure and resting heart rate decreased significantly, and the proportion of officers who passed an ergometer test simulating job demands increased from 59.2% to 76.3%. Medical referrals and health-related changes in Job status decreased during the program. On-the-job injuries and cardiovascular events, which previously had been increasing, also declined.