University students play a significant role in shaping the future of nations and an effective university environment that can achieve psychological and cognitive engagement is very important. This research aims at identifying the mediating role of mental mindfulness between academic self-efficacy and engagement (psychological and cognitive) of university students. The self-efficacy scale, the mental mindfulness scale, and the university students' psychological and cognitive engagement scale were applied to a sample of (340) university students. Results demonstrated that academic self-efficacy mediates the relationship between mental mindfulness and psychological and cognitive engagement of university students. These results can be utilized in developing university students' mental mindfulness and providing those in charge of educational planning and policies with practical results that are beneficial in enhancing university students' self-efficacy, mental mindfulness, and engagement. Keywords:  Self-efficacy, mental mindfulness, engagement, mediating variable