Epimastigotes and trypomastigotes of T. cruzi obtained from acellular culture as well as bloodstream trypomastigotes agglutinate with concanavalin A (Con A). Con A-binding sites were also localized on the cell membrane by using the Con A-horseradish peroxidase-diaminobenzidine method. Passage of epimastigotes and trypomastigotes from acellular culture through DEAE-cellulose column did not affect Con A-binding sites as detected by agglutination and electron miscroscopy.