Aim <p>Physical activity has been linked to better mental and emotional health, especially in the university context. This study was conducted to analyse the relationship between physical activity levels and various indicators of psychological well-being in university students.</p> Subject and methods <p>A cross-sectional study was conducted with 1268 Spanish university students (823 women and 445 men). Validated questionnaires were used to measure physical activity level, perceived stress, self-esteem, life satisfaction, emotional and behavioural difficulties, and emotional intelligence. Kruskal–Wallis tests and linear regressions were applied to analyse differences and associations between levels of physical activity and psychological variables, including analysis by gender.</p> Results <p>Increased physical activity was associated with lower levels of perceived stress and emotional and behavioural difficulties, as well as higher self-esteem, greater life satisfaction and better scores on emotional clarity and repair. Gender analysis by level of physical activity showed that men had lower levels of stress and emotional difficulties than women at all levels, but higher scores on emotional clarity and emotional repair. Women scored higher on emotional attention. In addition, men showed significantly higher self-esteem at low and moderate levels of physical activity, with no differences at the high level.</p> Conclusion <p>Regular physical activity is associated with a more balanced psychological profile, characterised by lower stress levels and greater emotional well-being. Furthermore, the results suggest gender differences in some indicators of well-being, reinforcing the need to design health promotion strategies tailored specifically to men or women. Promoting active university environments can contribute to improving students’ mental health and quality of life.</p>