Proanthocyanidins (PACs), present in a wide variety of food products and beverages, are the second most abundant class of phenolic compounds in our diet. These polyphenolic compounds are found in high proportions in cocoa products, seeds and skins of grapes, green and black tea, cinnamon and berries, among others. These compounds possess multiple therapeutic effects including anticancer, antimicrobial activity, cardioprotective role, prevention of atherosclerosis, and neuroprotective action. Many of these pharmacological benefits, including their neuroprotective action, are attributed to their significant antioxidant activity as free radical scavengers and as modulators of oxidant/antioxidant status. This book discusses food sources, the antioxidant properties and health benefits of proanthocyanidins.