https://www.selleckchem.com/products/sant-1.html hese damaging effects and provides a promising foundation for future studies aimed at developing noncultured, cell-based therapies for clinical implementation. Repetitive thinking as a transdiagnostic factor has an essential role in the development and maintenance of emotional disorders. Two versions of the Repetitive Thinking Questionnaire (31-item and 10-item) are the most known measures used for assessing repetitive thinking in clinical and non-clinical samples, and the present study developed to evaluate psychometric properties and factor structure of the Persian version of them. Participants are 592 students assessed by 31-item Repetitive Thinking Questionnaire, 10-item Repetitive Thinking Questionnaire, Ruminative Response Scale, Perseverative Thinking Questionnaire, Beck Depression Inventory- second edition, the Beck Anxiety Inventory, and the Depression, Anxiety, Stress Scale-21. Exploratory and confirmatory factor analysis were used to determine construct validity. The findings showed that the RTQ-31 and RTQ-10 demonstrated excellent internal consistency and good test-retest reliability (α=0.946 r=0.844) and (α= 0.903 r=0.776) respectively. Also, five items were omitted from the original version due to insufficient factor loadings; this study showed that the 26-item version has a two-factor structure, and the short version has a unidimensional structure. respectively. Finally, it is found that repetitive thinking has a positive and powerful relationship with other measures of rumination and symptoms of depression, anxiety, and stress. Persian versions of the Repetitive Thinking Questionnaire have a good factor structure and psychometric properties, and can be used in clinical papulation and related studies. Persian versions of the Repetitive Thinking Questionnaire have a good factor structure and psychometric properties, and can be used in clinical papulation and related studies. The existence of a general fa