Background: Essential oils have gained massive attention. We aimed to assess the effects of inhalation of Clinopodium serpyllifolium and Cymbopogon citratus volatile oils on exercise performance and lung function. Methods: Twenty physical education students were randomly assigned into two groups: Clinopodium serpyllifolium and Cymbopogon citratus (10 participants each). One group was nebulized with Clinopodium serpyllifolium oil and the other by Cymbopogon citratus oil at a concentration of (0.02 ml/kg of body mass) which was mixed with 2 ml of normal saline before 800 m running tests. Lung function tests were measured using a spirometer pre and post nebulization. Results: There was a significant increase in Forced Expiratory Volume in the first second and Forced Vital Capacity after inhalation of both oils. The normal spirometry after inhalation of C. serpyllifolium oil increased by 30%. A sharp decrease in mild spirometry (50% before to 10% after inhalation of the C.citratus oil) was observed. Significant reductions in the means of the running time were observed. Conclusion: Our findings support the effectiveness of C. serpyllifolium and C. citratus essential oils on exercise performance and respiratory function parameters. Keywords: Clinopodium serpyllifolium, Cymbopogon citratus, essential oil, lung function, athletic performance.