Background and Objective:Some studies suggest that psychological condition and stress can play role in the development of recurrent aphthous stomatitis (RAS). The purpose of this study was to evaluate salivary cortisol changes and psychological conditions in patients with RAS.Materials and Methods:Twenty-seven patients (13 males and 14 females, mean age of 32.8 (±10.2) years) with minor RAS and 27 age- and sex-matched controls without RAS participated in this study. The concentration of cortisol (nanomole/L) was measured in samples of unstimulated saliva from patients and controls two times; once during the presence of active lesions and once again when the lesions had healed by immunologic assay. The Hospital Anxiety and Depression Scale was employed to determine psychological condition. Visual analog scale for pain severity was recorded for patients with active lesions episode. Data were analyzed by the SPSS software (version 18.0) using paired and unpaired t-tests and Pearson correlation coefficient.Results:Salivary cortisol level was lower in patients during active lesions (12.4 ± 5.1) and healing (10.5 ± 3.9) episodes compared to the controls (13.1 ± 3.6) (P = 0.583, P = 0.015; respectively). There was no significant difference in salivary cortisol between active lesions and healing episodes (P = 0.943). Anxiety and depression represented no significant differences between active lesions and healing episodes (P > 0.05). Anxiety and depression levels in patients were significantly higher than in controls (P < 0.05). Pain severity in active lesions was not significantly correlated to salivary cortisol level, and anxiety or depression scores (P > 0.05).Conclusion:The findings showed that occurrence of RAS was associated with anxiety and depression but not with alterations of salivary cortisol level.