The present study was carried out to investigate the effect of exposure of Cambodian black pepper essential oil on the human electroencephalographic (EEG) activity. In the EEG study, 20 men and 20 women healthy volunteers participated. The EEG readings were recorded from 32 electrodes placed on the scalp according to the International 10‐20 system and 25 EEG indices were analyzed. The essential oil of black pepper mainly contains β‐caryophyllene (30.53%), 3‐carene (19.85%), limonene (14.26%), β‐pinene (9.45%), and α‐pinene (5.25%). The EEG data showed that the exposure of black pepper essential oil exhibited different brain wave activity according to the gender. In women, a significant increase of spectral edge frequency 50% of alpha at C4 region was observed due to the exposure of black pepper essential oil. In the case of men, relative gamma, the ratio of sensorimotor rhythm to theta, spectral edge frequency 50%, spectral edge frequency 90%, and spectral edge frequency 50% of alpha significantly increased during the exposure of black pepper essential oil. The result revealed that the gender variation plays a major role in the EEG activity of black pepper essential oil and the exposure of black pepper essential oil may improve the cognitive functions.