Maca plant belongs to Brassicaceae such as broccoli, cabbage and radish, and has a tuberous root. With the declaration of The Food and Agriculture Organization (FAO) that maca is a forgotten and disappearing plant, the fresh, dried, powder and organic forms of it take part in nutrition as a food supplement world-wide. Studies have focused on antioxidant effects depending on its bioactive components such as phenols, glucosinolates, alkamides and polysaccharides. Antioxidant enzymes and their ability of inhibition the free radicals in blood and tissues were measured to determine the antioxidant effects. The research results have suggested that these compounds present the antioxidant effect by increasing enzyme activity and scavenging free radicals. Yet further experiments are needed to understand this relation between antioxidant activity and maca’s antioxidants. The objective of this chapter is to carry out the possible antioxidant activity of maca in human and animal nutrition related to its active compounds such as: phenols, glucosinolates, alkamides and polysaccharides.