Background: Studies has shown the effect on environmental conditions on psychological well-being. In this regard, psychological characteristics have an important role. This study aimed to investigate the role of mindfulness, psychological flexibility and integrative self -knowledge amonge the university students. Material and Methods: This cross-sectional study was performed on the students of Kashan university of medical sciences (n=300) and based on quota sampling, a number of students (n=241) were selected based on the faculty and the major of the study. The administered tools were Ryff scale of psychological well-being (RSPWB-18), mindfulness (MAAS), acceptance and actions (AAQ-II) questionnaires and integrative self-knowledge scale (ISKS). Finally the data were analyzed using correlation and stepwise regression. Results: Pearson correlation disclosed a positive and considerable relation between mindfulness, integrative self-knowledge, psychological flexibility and psychological well-being. In addition, the findings showed significant role of mindfulness, integrative self-knowledge and psychological flexibility to predict the psychological well-being of the students; so these variables can predict 21 of psychological wellbeing changes. Conclusion: This study disclosed that the mindfulness, psychological flexibility and integrative self -knowledge can in part specify the variance of psychological well-being
