Spleen cells from mice immunized with insect-derived Typanosoma crUm metacyclic trypomastigotes were used to obtain Colombian strain-specific monoclonal antibodies. At least 4 different strain-specific antigens were recognized by the monoclonal antibodies on epimastigotes or metacyclic trypomastigotes. There was no reactivity with other stages of Colombian strain T. cruzi, nor with any stage of 15 other T. cruzi strains or isolates, nor with 22 other Trypanosomatidae. One of the monoclonal antibodies was used to identify, by indirect immunofluorescence, Colombian strain flagellates in cryostat sections or glass-slide smears of the insect vector’s intestine.