Objectives. The purpose of this study was to investigate the analgesic and antistress effect of clary sage-inhalation in periodontitis patients. Methods. Thirty-five patients with periodontitis, who were classified under Russell`s Periodontal Index, were studied from September to December 2009. All patients understood the purpose of this study and written informed consent for the study was obtained. Results. Clary sage-inhalation was conducted during the treatment period. Blood pressure, pulse, visual analog scale, and salivary cortisol levels were measured before and after treatment. The visual analog scale score which represents subjective pain perception in the experimental (clary sage-inhalation) group was significantly lower than that in the vehicle (almond oil-inhalation) or control (saline-inhalation) group. In addition, the experimental group showed the lowest systolic and diastolic blood pressure and pulse rate among the three groups. However, there was no significant difference in salivary cortisol level among the three groups. Conclusions. Clary sage-inhalation is effective in alleviating pain and blood pressure. These results suggest that clary sage-inhalation can be a useful method for the relief of pain during the treatment of periodontitis.