The effect mechanism of mindfulness on athletic performance is still trying to be understood. In the present study, we examined the mediating role of depression, anxiety, and stress in the relationship between mindfulness and self-rated performance.Three hundred sixty-three student-athletes (61.2% male, 38.2% female, M-age = 21.47, SD = 3.30) were asked to fill the Mindfulness Inventory for Sport (MIS), the Depression Anxiety Stress Scale-21 (DASS-21), and the Self-rated Performance Questionnaire. While mindfulness was positively related to athletic performance, it was negatively related to depression, anxiety, and stress. The relationship between mindfulness and athletic performance was partially mediated by depression, anxiety, and stress. While the cross-sectional design does not permit causal inferences, these findings raise the possibility, in this population, that mindfulness may positively affect perceived performance by reducing depression, anxiety, and stress.