Since many undesired oxidation processes, including food decay and a variety of diseases, anthocyanins from grape skins are potential added value products that can be applied as natural food additives and disease chemopreventive agents. Anthocyanins are widely dispersed throughout the plant kingdom. The world annual consumption of anthocyanins has been estimated as 10,000 tons from red grapes only. As well as acting as attractants for pollinating insects, anthocyanins in the epidermis have a protective role, acting as a filter and reducing the levels of harmful irradiation reaching mesophyll cells. Today, natural antioxidants are still under intensive study and represent a currently emergin concept in nutrition. The intent of this book is to identify and quantify anthocyanins present in thirteen traditional Greek red grape varieties and four of the so-called international cultivars grown in Greece and to evaluate their antioxidant activity. Their identification and quantificatio were carried out using High Performance Liquid Chromatography (HPLe. Antioxidant activity was evaluated by measuring the scavenging ability of skin extracts using the DPPH assay.