This study aimed to evaluate the anxiolytic effect of Mentha piperita essential oil on state and trait anxiety. Methods: The essential oil was extracted by hydrodistillation, and its chemical composition was analyzed using Gas Chromatography-Mass Spectrometry (GC-MS). A total of 93 participants were divided into a control group (CG) and an experimental group (EG), with 47 participants in the EG receiving MPEO aromatherapy and 46 in the CG. Anxiety levels were measured using the State-Trait Anxiety Inventory (STAI) at pretest and posttest phases. Results: GC-MS analysis showed that menthol had the highest concentration (42.56%), followed by menthone (19.24%) and linalool (11.68%). Mixed model analysis revealed that group assignment (EG vs. CG) was a significant predictor of posttest state anxiety (F=16.508, p=0.001) and trait anxiety (F=9.091, p=0.003), independent of pretest scores, supp...