The inhibiting effect of melanin synthesized from dihydroxyphenylalanine (DOPA), dopamine, adrenaline and adrenolutin on the ultraviolet- or the Fe2+-ascorbic acid-induced peroxidation of cardiolipin liposomes has been studied. All these melanins are able to inhibit both the ultraviolet- and the Fe2+-ascorbic acid-induced lipid peroxidation. Antioxidative activity of melanins enhances in the order: dopamine-melanin < melanin synthesized from dopamine in the presence of Cu2+ < DOPA - melanin < melanin synthesized from adrenaline in the presence of Cu2+ congruent-to adrenolutin-melanin, and correlates with their ability to scavenge superoxide anion radical. The optical screening effect of the investigated melanins in the inhibition of lipid peroxidation was not higher than 15% for the most active melanins.