Purpose: The purpose of this study was to evaluate the effects of inhaled clary sage (Salvia sclarea L.) oil or linalyl acetate on patients’ anxiety and stress levels before undergoing chemotherapy. Methods: Forty-five eligible participants were randomly assigned to inhale clary sage oil, or linalyl acetate, each at concentrations of 5% vol/vol in almond oil or pure almond oil (control). State-trait anxiety inventory (STAI), Stress rating scale, anxiety-visual analog scale (Anxiety-VAS), stress-visual analog scale (Stress-VAS), blood pressure, and heart rate were measured before and after the inhalation prior to undergoing chemotherapy. Results: Anxiety-VAS and Stress-VAS were significantly lower after than before inhalation of clary sage oil (p<.01 and p<.05, respectively) and linalyl acetate (p<.05 and p<.05, respectively), despite having no significant difference in the three groups compared with control group. Systolic (p<.05) and diastolic (p<.01) blood pressure before undergoing chemotherapy were significantly lower after than before inhalation of linalyl acetate, while there was no significant difference in after than before inhalation of clary sage oil, despite both reducing levels of anxiety and stress. Conclusion: These findings suggest that linalyl acetate inhalation may be inappropriate in lowering anxiety and stress in patients undergoing chemotherapy, despite its anxiolytic and antistress effects, while clary sage oil inhalation may be useful in reducing anxiety and stress in patients undergoing chemotherapy, which has a risk of hypotensive side effects.