Three prenylated flavonoid derivatives; 5,7,4'-trihydroxy-8-(3"'-methylbut-2"'-enyl)-6-(2"-hydroxy-3"-methylbut-3"enyl) isoflavone (isoerysenegalensein E), 5,7,2'-trihydroxy-4'-methoxy-5'-(3"-methylbut-2"-enyl) isoflavanone (lysisteisoflavanone), 5, 4'-dihydroxy-6-(3"'-methylbut-2"'-enyl)-2"-hydroxyisopropyl dihydrofurano [4",5":8,7] isoflavone (isosenegalensin), together with the four known flavonoids abyssinone V-4'-methylether, alpinumisoflavone, wighteone and burttinone were isolated from the stem bark of Erythrina lysistemon Hutch. (Leguminosae). Structures were elucidated by spectroscopic methods.