Purpose : The purpose of this study is to present a model of psychological well-being based on the components of psychological capital and psychological flexibility by mediating role of mindfulness. Methodology : This study is a descriptive research and subjects are composed of 350 masters' students of psychology from Islamic Azad University in Tehran that are selected using ‘stratified random sampling proportional to size’ method. In this method, from each unit of the university, a sample was selected independently and proportional to size of that unit. The participants responded to psychological well-being questionnaire (Ryff, 1989), psychological capital questionnaire (Luthans et al, 2007), Acceptance and action Inventory (Bond et al, 2011) and Mindfulness Questionnaire (Buchheld et al, 2006). Data are analyzed using path analysis through LISERL 8.8. Finding: The results show that cognitive flexibility, hope, optimism, self-efficacy, resiliency and mindfulness directly predict psychological well-being (P<0.01), and on the other hand, cognitive flexibility, hope, optimism, self-efficacy and resiliency indirectly predict psychological well-being by mediating role of mindfulness (P<0.01). Conclusion: So a program can be developed to enhance cognitive flexibility and components of psychological capital and mindfulness, through which students’ level of psychological well-being would be improved. This study was applied in terms of objective and combined.
