Examination of the aerial parts of Eriostemon myoporoides has led to the isolation of fifteen compounds including eight novel coumarins: (-)2'B~2r,3-epoxy-3-methyl-l-oxobutyl)-2'-deoxybruceol, (-)2'/?-(3-methyl-loxobut-2-enyl)-2'-deoxybruceol, (-)2'/I-{ (E)-3-hydroxy-3-methylbut-l-enyl}-2'-deoxybruceol, (-)2'/?-{ (E)-3 hydroperoxy-3-methylbut-1-enyl}-2'-deoxybruceol, (-)Z'P-(3-methyl-l~,2C,3-trihydroxybutyl)-2'-deoxybruceol, (-)2'B-(2S-hydroperoxy-3-methylbut-3-enyl)-2'-deoxybruceol, (-)2'fi-(2t-hydroxy-3-methyl-l-oxobutyl)-2' deoxybruceol and 8-geranyl-5,7-dihydroxycoumarin; three novel geranyl substituted benzaldehydes: 3-(6Chydroperoxy-3,7-dimethylocta-2,7-dienyl)-4-hydroxybenzaldehyde, (E)-3-(7-hydroperoxy-3,7-dimethylocta-2,5-dienyl)-4-hydroxybenzaldehyde and (Z)-3-(7-hydroperoxy-3,7-dimethylocta-2,5-dienyl)-4-hydroxybnzaldehyde; two known coumarins: scopoletin and scoparone; a dihydrocinnamic acid derivative: eriostemoic acid and a simple dial: 4-hydroxy-1,3-benzenedicarboxaldehyde. The chemotaxonomic significance of the sesquiterpenyl coumarins in the genus Eriostemon is discussed.