The chloroform extract of the aerial parts of Helianthus heterophyllus afforded the heliangolides 2',3'-dihydroleptocarpin and 2',3'-dihydroniveusin C and the new coumarin (-)-8-methoxyobliquin. Other constituents were various ent-kaurenoic acids, (+)-vomilifoliol, dehydrovomilifoliol, 9-hydroxy-4-megastigmen-3-one, 9,12,13trihydroxy-octadeca-10(E),15(2Z)-dienoic and 9,12,13-trihydroxyoctadec-10(E)-enoic acid. 2.6-dimethoxybenzoquinone and vanillin.