Recebido em 10/10/11; aceito em 17/1/12; publicado na web em 15/5/12 A chemical investigation of Eugenia brasiliensis Lam. (Myrtaceae) leaves led to the isolation of a-amyrin and b-amyrin (in a mixture), betulin, 29-hydroxy-oleanolic acid, quercetin, catechin and gallocatechin. Herein, the identification of 29-hydroxy-oleanolic acid is reported for the first time in the Myrtaceae family. Moreover, in this study, the extract, fractions and six of the seven compounds were monitored for toxicity toward Artemia salina, antibacterial and acetylcholinesterase inhibitory activity. The crude ethanol extract of the leaves and fractions were found be active on A. salina toxicity bioassay.