Carotenoids, naturally occurring pigments, are exclusively synthesized by plants and micro-organisms. Humans are not able to synthesize carotenoids and depend entirely on dietary intake of fruits, vegetables and nutritional supplements. Lycopene, a red coloured carotenoid phytonutrient, naturally produced in highest concentration in tomato and tomato-based products is a potent 1O2 quencher, and has been found to possess "antioxidant" and "antitumor" properties that mitigate the damaging effects of oxidative stress. This book discusses food sources, the potential role in human health of lycopene, and the antioxidant effects lycopene possesses.