Docosahexaenoic acid (DHA), the end-product of the n-3 family fatty acid, is an abundant component in the brain phospholipids, and a major nutrient of marine lipids. It is accumulated in this compartment from the non-esterified pool bound to blood plasma albumin. 1-Lyso,2-DHA-glycerophosphocholine is another form, also bound to albumin, which appears even more efficient than non-esterified DHA for its brain accretion. DHA, as a highly unsaturated fatty acid, may affect the cell redox status. As expected, it may promote lipid peroxidation at high concentrations, but most interestingly may prevent it at low concentrations. DHA is also a fairly good substrate of lipoxygenases, especially the n-9 and n-6 ones. Hydroxy derivatives, i.e., docosanoids, exhibit potent biological activities, which may explain part of the potential benefit of DHA in the brain and vascular bed.