The cost of health care continues to rise as we deal with changes in the natural history of disease and deploy increasingly advanced medical technology for diagnosis and treatment. A different focus must be established if we are to control both disease and our health-care budget. One area of promise is preventive medicine. Improved fitness through exercise is one component in this approach, and increasing numbers of the general public are choosing this positive lifestyle change. Patients are seeking the advice and blessing of the primary-care physician before engaging in physical activity. In order to prescribe safe exercise, physicians must be able to screen individuals for possible contraindications and to evaluate their current fitness levels. This article describes a comprehensive cardiovascular system screen, including history, physical, lab work, and fitness appraisal, and reviews the current recommendations for treadmill stress testing.