Aromatherapy is one of the complementary therapies that is carried out through essential oils. The essential oil of Rosmarinus Officinalis L. (rosemary) has been gaining attention in aromatherapy research, as studies have shown that the use of this oil is one of the promising non-pharmacological therapies for cognition. In this way, inhalation of rosemary essential oil is one of the forms of cognitive intervention across different age groups. The study will aim to analyze the effect of rosemary essential oil, with the following chemotypes: camphor and cineole, on the cognitive performance of adults. Significant differences are expected between the control (placebo) and experimental groups, given that studies in humans have already shown significant effects of rosemary essential oil on cognition. Considering the inclusion and exclusion criteria of the study, participants will be allocated to either the control or experimental group. Consequently, the application of the tests will be carried out neuropsychological tests for the pre-test evaluation, followed by aromatherapy (acute phase) and the reapplication of the tests (post-test phase 1). For 14 days, the participants will chronically use rosemary essential oil and at the end they will participate in the reapplication of the neuropsychological tests (post-test phase 2). For inferential analyses, the ANOVA test or its non-parametric equivalent will be used. In addition, linear regressions may be performed to verify how much the essential oil can predict the outcome of the study's dependent variables. Effect Size will also be calculated. Keywords: Chronic intervention; neuropsychology; aromatherapy.