Trypanosome evansi is a widely distributed hemoflagellate causing severe economical losses in farm animals. The present study is a trial to control Trypanosome evansi using Nige/la safive oil extract as a medicinal plant. For this purpose, thirty-seven male albino rats weighing 100-150 g each were divided into 5 groups. Rats of groups I and II were infected experimentally with Trypanosome evansiobtained from naturally infected camels and treated with Nigeria sative oil extract on 3 and 12 days post-infection (d.p.i), respectively, while rats of group III were used as prophylactic. Group IV was the control infected non-treated rats, while group V was the control non-infected non-treated one. The parasitaemia level was reduced in both treated and prophylactic groups in comparison with the control infected non treated one. Some morphological changes appeared in Trypanosoma individuals in both treated and prophylactic groups post-treatment with Nigella saliva oil extract. These changes induded lightly stained cytoplasm, degeneration of nucleus, disappearance of kinetoplast, flagellum and undulating membrane, swelling of the trypanosomes, apperance of vacuoles behind kinetoplast and oval-shaped trypanosomes. Nigeria safiva decreased the lethal effect of Trypanosoma evansi through prolonging the survival time in treated and prophylactic rats.