Abstract: The activity of some medicinal plants used in Sudan was studied in rats experimentally infected with T. evansi. Tinospora bakis, Argemone maxicana and Aristolachia bracteolata were evaluated for in vivo activity against Trypanosoma evansi infectin in rats. The three plants tested in the preset study were selected on the basis of information from traditional healers on their curative effect in the treatment of malaria or sleeping sickness. The plant extracts were administered orally at dose rates of 100, 250 and 500 mg kg-1 BW for both methanolic and chloroformic extracts. The result was compared to Cymelarsan which was given at the recommended dose rate of 2.5 mg kg-1 BW subcutaneously. A daily program for the parsitaemia for all methanolic and chloroformic extracts in infected or uninfected rats were followed for 30 days after treatment. Blood was collected every week for analysis. Tinospora bakis extract was found to be effective in cleaning the parasite for a considerable time and extending life-spam of the treated rats. Argemone maxicana on the other hand was found to be more effective in cleaning or reducing the parasitaemia for both methanolic and chloroformic extract. Aristolachia bracteolate chloroformic extract gave a very good trypanocidal effect where clearance of the parasite was 100%. Whereas the methanolic extract gave a limited trypanocidal effect.