The renin angiotensin system (RAS) maintains the cardiovascular homeostasis and is involved in the pathogenesis of several disorders related to heart and kidney. There are several peptides under RAS in which angiotensin (Ang) II is the major contributor. In this book, the authors present topical research on angiotensin. Some of the topics discussed include the influence of renin-angiotensin-aldosteron system genes on hypertrophy development in hypertrophic caradiomyopathy; cardiac renin angiotensin system and exercise training; the role of the counter-regulatory renin angiotensin system in the heart and new roles for the neuropeptide angiotensin II.