Antimalarial activity of the crude aqueous leaf extract of Pyrenacantha staudtii was evaluated using chloroquine-sensitive Plasmodium berghei infection in mice with an objective to finding scientific evidence for the use of the plant as traditional antimalarial remedy in Ido/Osi LGA of Ekiti state, Nigeria. The crude aqueous extract of P. staudtii Engl. (Icacinaceae) (100, 200 and 500 mg/kg) was administered orally to mice infected with P. berghei in 4 days suppressive test. The antiplasmodial effect during the test of the plant in blood was determined and the extract at these doses induced 58.0 to 63.4% activity in comparison with untreated (negative) control group. Chloroquine produced 100% activity. The antimalarial activity showed by P. staudtii during the test justifies its use in traditional medicine for treating of malaria in the area.