The essential oils from the aerial parts of three species of Senecio (Senecio subulatus var. salsus, S. subulatus var. erectus, Senecio viridis and Senecio argophylloides.) were collected in different phytogeographic areas of Northern Argentina. The oils were obtained by hydrodistillation and characterized by GC and GC-MS analyses. Monoterpene hydrocarbons dominated the chemical profile of the oils with ß-pinene (17–31 %), p-cymene (18–33 %) and J-terpinene (16–54 %) as the main constituents of S. subulatus and Ot-thujene (13–32 %), camphene (53–9 %), sabinene (12–7 %) and ß-phellandrene (11–16 %) for S. argophylloides and S. viridis, respectively.