The levels of biogenic amines in Brazilian beers were investigated for the "rst time. Ninety-one samples of "ve types of beer purchased at retail stores were analyzed by reversed-phase ion-pair chromatography and #uorimetric detection after post-column derivatization with o-phthaldialdehyde. Putrescine, agmatine and tyramine were the most prevalent amines (100%) followed by histamine, tryptamine, spermine (40}42%) and 2-phenylethylamine (18%). The mean total amine level was 19.3 mg/l, with signi"cantly higher and lower levels detected in stout and ice beers, respectively. Agmatine contributed the most (40}56%) to the total amine content of beers, followed by putrescine (13}42%) and tyramine (7}28%). Smaller variation on amine levels was observed for amines inherent to raw materials (putrescine, agmatine) than to those which may be formed during brewing (tryptamine, 2-phenylethylamine, tyramine). No signi"cant di!erence was observed in putrescine, histamine, spermidine, 2-phenylethylamine and spermine levels among the di!erent types of beer. Higher tyramine and tryptamine levels were detected in stout. The levels of histamine and tyramine detected are below levels that may elicit direct adverse reactions. However, patients being treated with monoamine oxidase inhibitors should avoid stout and limit the consumption of the other types of beer.