Purpose: This study was done to examine the effects of Aroma inhalation therapy on test anxiety, stress and serum cortisol in nursing students. Methods: The study design was a pre posttest randomized design with a pre-survey, a 5-day experimental treatment (2012.11.17-21) and a post survey. Participants were 65 students - 31 in the aromatic inhalation group and 34 in the control group. The pre-survey included general demographic characteristics and test anxiety, stress and serum cortisol levels for all students. The experimental group received the aromatic inhalation using aroma oil (mixed Maychang, lavender, rosewood essence - ratio of 3:5:2). Results: The experimental group treated with aromatic inhalation scored significantly lower for test anxiety (t=-2.330 p=.023), physical stress (t=-2.910 p=.005) and psychological stress (t=-3.285 p=.002) compared to the control group. However, there were no differences in serum cortisol levels (t=0.228 p=.820). Conclusion: Results indicate that Aromatic inhalation, using maychang, lavender and rosewood essential oils, contributes significantly to reducing anxiety and stress among nursing students, and can therefore be an effective intervention for anxiety and stress.