Antioxidant properties of the principal biogenic amines were determined in vitro by four analytical methods—Folin Ciocalteu, DPPH, enzymatic and inhibition of lipid peroxidation—in order to avoid possible measuring-method linked mistakes. Different results are obtained, depending on the parameters that each of them measures. The combination of the data indicates that all examined amines show antioxidant characteristics: in particular, tyramine, serotonin, L-norepinephrine, (-)-epinephrine and dopamine owing to their (poly)phenolic structure too, while aliphatic polyamines-spermine, spermidine, putrescine and cadaverine-histamine, melatonin and tryptamine appear to act specifically on the oxygen-consuming species involved in the lipid peroxidation of polyunsaturated fatty acids.