Malaria is an increasing worldwide threat, with more than three hundred million infections and one million deaths every year. In Africa and elsewhere, medicinal plants including Faidherbia albida Del. are still widely used in the treatment of malaria and other ailments. Previous studies in our laboratory have shown that the ethanolic stem bark extract of Faidherbia albida possesses antipyretic, anti-diarrhoeal and anti-inflammatory properties. The present study was carried out to investigate its in vivo antiplasmodial effect in mice. The in vivo anti- plasmodial effect against early infection, curative effect against established infection and prophylactic effect against residual infection were studied in chloroquine - sensitive Plasmodium berghei berghei NK65- infected mice. The extract at all the doses (100, 200 and 400 mg/kg, p.o.) used, produced significant (P<0.05), dose - dependent activity against the parasite in the suppressive, curative and prophylactic tests. The result suggests that Faidherbia albida ethanolic stem bark extract possesses potent antimalaria effect.