Six functionalized 1,3-dienes were synthesized using cross-coupling reactions, catalyzed by palladium complexes, between alkenylboronic acids and alpha-bromo-alpha,beta-unsaturated carbonylic compounds. Their cytotoxicity against epimastigotes of Trypanosoma cruzi and fibroblastic Vero cells was evaluated, using concentrations ranging from 100 microM to 2.5 mM in experiments with three incubation times (4, 8 and 16 h). These tests were performed using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] colorimetric bioassays and its further reduction to formazan, according to the viability of the parasites and cells. With the exception of (5E,6E)-5-benzylidene-2-methylundec-6-en-4-one, all compounds were cytotoxic to both Trypanosoma cruzi and Vero cells, however differential values of IC50 were observed for two of these compounds. A possible structure-activity relationship is discussed.