The acetone extracts of the root bark and stem of Erythrina sacleuxii showed antiplasmodial activities against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum. Chromatographic separation of the acetone extract of the root bark afforded a new isoflavone, 7-hydoxy-4’-methoxy-3’prenylisoflavone (trivial name 5-dexoxy-3’- plasmodial principles. Flavonoids and isoflavonoids isolated from the stem bark of E. sacleuxii, were also tested and showed antiplasmodial activities. The structures were determined on the basis of spectroscopic evidence.