The role of dispositional mindfulness on stress in student-athletes and factors that mediate this relationship has yet to be examined. Accordingly, the purpose of this study was to investigate the relationships between the facets of mindfulness and life stress in student-athletes and whether these relationships are mediated through coping effectiveness and decision rumination. Participants were 202 student-athletes who completed validated measures of dispositional mindfulness, student-athlete life stress, decision rumination and coping effectiveness in sport. Results indicated that the acting with awareness and nonjudging facets of mindfulness were negative predictors of life stress, whereas the observe facet was a positive predictor of life stress. Mediation analyses revealed that these relationships were mediated through coping effectiveness and decision rumination. Findings provide new insight into the role dispositional mindfulness plays on student-athlete perceptions of life stress and implications for practitioners are discussed.