Open AccessThe resurgence of Human African Trypanosomosis and Animal African Trypanosomosis in the latter part of the 20th century after it had been brought largely under control in the 1960 has been alarming. Methanolic extract of stem bark of Ximennia americana were partitioned to obtain their major phytochemical fractions, these were evaluated for their in vitro and in vivo antitrypanosomal activities against Trypanosoma congolense. The Flavonoid fraction significantly (P<0.05) inhibited the motility of the blood stream forms with 10mg/ml. However, when the infected mice were treated at 5, 10 and 25mg/ml of the flavonoid fractions, there was a suppression of the growth of the parasites in a dose dependent manner with the 25mg/ml producing the maximum effect. The results further confirm the ethnopharmacological usage of Ximenia americana against Trypanosomosis. KEYWORD: Flavonoid , Ximenia americana, antitrypanosomal activity