Isoflavonoids are a valuable group of natural products and are primarily synthesized in leguminous plants, where they play important roles in plant defense. They also have significant health benefits for animals and humans and have been ascribed various estrogenic, antiangiogenic, antioxidant, and anticancer activities, leading to their popularity as dietary supplements. This book gathers and presents topical research data on isoflavones including bioactive isoflavones and their implications in cancer treatment and prevention, soy protein and isoflavones in the prevention of cardiovascular disease and the processing techniques on isoflavone profiles.