The investigation of 17 Australian Helipterwm species afforded 32 new sesquiterpene lactones (four germacranolides, 22 guaianolides and six eudesmanolides), a bisabolene derivative, four ent-beyerene derivatives, cembrol, an isomer of trixagol and four alkylated salicyclic aoids. The structures were elucidated by high field NMR techniques. Three South African species gave no characteristic compounds.