BACKGROUND: Breast cancer survivors not only experience distressing physical symptoms associated with treatments, but also are faced with psychosocial challenges. Despite growing scientific evidence that physical activity (PA) may mitigate psychosocial distress experienced by women treated for breast cancer, the literature is equivocal. PURPOSE: This study investigated the relationships between cardiorespiratory fitness (CRF), PA, and psychosocial factors in breast cancer survivors. METHOD: Data involving overweight or obese breast cancer survivors (N = 260) were examined. CRF was determined by a submaximal graded exercise test. PA, depressive symptoms, total fatigue, and global self-esteem were assessed with self-report measures. Pearson's correlations were conducted to determine associations among CRF, PA, depressive symptoms, total fatigue, and global self-esteem. Multiple regression models, with age and body mass index as covariates, were performed using continuous levels for CRF and PA. RESULTS: Bivariate correlations suggested that CRF and PA were unrelated to the psychosocial variables. One of the regression models identified a marginally significant (P = 0.06) inverse association between depressive symptoms and PA. CONCLUSION: CRF and PA were not associated with psychosocial factors in this sample of breast cancer survivors. However, minimal PA was reported by the majority of participants, so low PA variability likely influenced these findings.