the effects of 25, 50, 75 and 100% of light intensity (137, 254, 406 and 543 mol photons m-2 second-1, respectively) on aspects related to volatile synthesis in menthol mint were investigated. fresh weight production, glandular trichome density and essential oil content showed a significant linear positive correlation with light intensity. plants under low light intensity (25%) produced an essential oil with high levels of neomenthol, menthol and menthyl acetate. with 50 and 75% of light intensity plants showed an increase in expression of limonene synthase, limonene hydroxylase, (-)-isopiperitenol dehydrogenase, (+)-pulegone reductase and menthol dehydrogenase genes and an anticipation in oil maturity. with 25% of light intensity plants produced an essential oil with the best commercial profile. however, plants under 100% of light intensity produced more essential oil but with lower levels of menthol and higher levels of pulegone, that can be toxic for humans.