The constitutive isoflavones genistein, 2'-hydroxygenistein, wighteone and luteone have been isolated in varying amounts from methanolic leaf washings of eight species belonging to the legume genus Lupinus. These four compounds likewise occur in the flower buds, stems, roots and immature pods of L. albus, and in stems and roots of L. angustifolius and L. mutabilis. A minor isoflavone present in L. albus and L. luteus leaf washings has been identified by chemical and spectroscopic procedures as 5,7,4'-trihydroxy-3-methoxy-6-(3,3-dimethylallyl)isoflavone (lupisoflavone). Apart from genistein, 2'-hydroxygenistein, wighteone and luteone, the roots of L. albus also contain alpinumisoflavone, licoisoflavone B and 6,3'-di-(3,3-dimethylallyl)genistein (lupalbigenin)