Two amino-substituted isoflavones and one with an oxazole ring were isolated from the root bark of Piscidia erythrina. Their structures were established as 4'-amino-5,7,3'-trihydroxy-5'-methoxy-2',6'-di-(3,3-dimethylallyl)isoflavone, 4'-amino-5,7,3'-trihydroxy-5'-methoxy-8,2'-di-(3,3-dimethylallyl)isoflavone and 7-hydroxy-5'-methoxy-2'-(3,3-dimethylallyl)-oxazolo-[4''',5''':4',3']isoflavone by spectroscopic and chemical methods. The first of these isoflavones was chemically converted to a compound which could also be obtained from the corresponding 4'-hydroxyisoflavone, erythbigenin.