Mentha piperita is a medicinal plant of the Labiatae family. this species produces valuable essential oil. In this study, the effect of eleven treatments of salinity and nanoparticles of iron oxide on the essential oil composition in M. piperita was investigated. Mature plants were collected at 90 days after planting. Essential oils were extracted from plant aerial parts using Clevenger-type apparatus, and the obtained oils were analyzed using gas chromatography and gas chromatography/mass spectrometry. The obtained results showed that the essential oil concentration differed between treatments. Application of iron nanoparticle increased essential oil amount, while salinity stress lovered its production. Menthone, menthol, 1,8-cineol, pulegone, menthofuran, cis-sabinene hydrate and germacrene D were the major essential oil compounds of control plants. The types and relative proportion of major components differed between studied treatments. Salt as well as iron nanoparticle stress had strong effects on essential oil production and composition.
