Abstract The Piper L. genus has a great variety of commercially, pharmacologically and biologically interesting species. The present study focused on essential oils extracted by means of the hydrodistillation from dry leaves of Piper cernuum, Piper glabratum, Piper hispidum and Piper madeiranum. The species supplied essential oil contents of between 0.5% and 0.8%. Gas chromatographyâmass spectrometry analyses revealed that the majority of components were -elemene (11.6%) and epi-cubebol (13.1%) for P. cernuum; -caryophyllene (14.6%) and longiborneol (12.0%) for P. glabratum; -pinene (12.0%), khusimene (12.1%) and -cadinene (13.2%) for P. hispidum; -caryophyllene (11.2%) and germacrene D-4-ol (11.1%) for P. madeiranum. The test carried out on the essential oils concerning the Artemia salina L. produced the following values for LC50 200.03 μg/mL (P. cernuum), 45.21 μg/mL (P. glabratum), 404.80 μg/mL (P. hispidum) and 49.64 μg/mL (P. madeiranum). Keywords: Piper cernum Piper glabratum Piper hispidum Piper madeiranum Artemia salina Acknowledgements We wish to thank the Fundação de Ãmparo a Pesquisa do Estado da Bahia (FAPESB) for their financial support, Else Franklin Guimarães for his botanical identification of the species, José Lima da Paixão for his help in collecting plant material and Prof. DSc. Alex-Alan Furtado for support in chromatography analysis.