Introduction: Diagnosis, treatment, consequences, side effects of treatment and recurrence of breast cancer lead to psychological reactions such as depression, anxiety and stress. These reactions can reduce quality of life in breast cancer patients by interference in function, control of symptom, making decisions about treatment, adherence to treatment regimens and social interaction.Methods: This research is based on correlation method. Statistical population was containing all women with breast cancer who had medical records in Imam Reza hospital of Kermanshah in 2010. Sample of research was 294 women with breast cancer that selected based on purposive sampling. Psychological distress assessed by DASS-21 and quality of life assessed by WHOQOLBREF. Data were analyzed statistically by version 11.5 of SPSS software. Statistic data analysis was based on descriptive statistics, Pearson correlation, inter regression analysis. P<0.05 was considered significant.Findings: Results showed that psychological distress has a significant negative relationship with quality of life (P<0.05). Based on inter regression analysis fifteen, twenty four, and twenty four percent of the variance in the physical health was explained by depression, anxiety and stress respectively. Also sixteen, nine, and nineteen percent of the variance in the psychological health was explained by depression, anxiety, and stress respectively. In the other hand, four, five, and six percent of the variance in the social relationship was explained by depression, anxiety, and stress respectively. Finally, twenty one, twelve, and fifteen percent of the variance in the environment health was explained by depression, anxiety, and stress respectively. Therefore, stress was strongest predictor of physical health, psychological health and social relationship and depression was strongest predictor of environment health.Conclusion: It is concluded that in women with breast cancer, psychological distress, especially stress and depression have important roles in reduce of physical and psychological health. This research showed that stress and depression lead to dissatisfaction of women with breast cancer from their social relationships and circumstances of their life environment. Therefore, attention to psychological distress and it's reduce should be consider as one of the essential priorities in psycho-medical interventions.