This study aimed to evaluate the susceptibility of Brazilian isolates of Trypanosoma evansi to suramin sodium. For this purpose, threeisolates ofT.evansi(LPV-2005, LPV-2009 and LPV-2010) and seventymice were used, with the animals divided in 10 groups (A, B, C, D, E, F, G, H, I and J) with seven animals each group. Mice of groups A, B, and C were infected with LPV-2005; Groups D, E and F with LPV-2009 and the groups G, H and I with LPV-2010. The group J was composed by healthy mice or uninfected. The parasitemia was monitored daily through blood smear, and the treatment of all groups was performed three days post-infection (PI), when all mice showed increased parasitemia. Groups A, D and G represented the positives controls, while groups B, E and H received a single dose of suramin sodium at 10 mg kg(-1) intramuscularly. Groups C, F and I were treated with three doses of suramin sodium at 10 mg kg(-1), respecting an interval of 24 hours between each dose. Negative blood smears from all animals were obtained 24 hours after treatment (AT), status maintained until the end of the experiment (50 days PI). The specific PCR for T. evansi was carried out from blood, showing negative results AT. Therefore, this study showed that a single dose of suramin sodium at 10 mg kg(-1) has the same efficacy of three doses, as recommended by the therapeutic literature. Furthermore, we observed that Brazilian isolates did not show resistance to the drug.