The 6th edition of the textbook Ellestad’s Stress Testing: Principles and Practice was written for the new and veteran clinician alike performing stress testing. Thoroughly updated, referenced and interspersed with case examples, the book reviews how to get the most out exercise testing, without and with ancillary imaging. In addition to evaluation of ST segment depression, other powerful tools to detect ischemia and forecast the future are reviewed to increase the diagnostic accuracy and prognostic ability of exercise testing. The recognition and significance of exercise induced arrhythmias and conduction defects are examined. When to convert to pharmacologic stress or add ancillary imaging, including myocardial perfusion imaging, echocardiography, coronary calcium scoring, and magnetic reference imaging are reviewed. The use of stress testing in the management of obstructive and non-obstructive coronary artery disease (CAD), heart failure, cardiac rehabilitation, peripheral vascular disease, congenital heart and other cardiovascular diseases (CVD) is examined. Options to optimize the diagnostic capabilities of exercise and other diagnostic testing for women are highlighted. Strategic use of exercise testing in the face of a decreasing burden of CAD in the developed world, as well as the opportunity to rely on exercise testing as the first test to evaluate CVD in the developing world, are reviewed. The fundamentals of exercise physiology and myocardial ischemia that serve as the foundation for exercise testing in health and disease are explained.