Background: Depression is the most common psychological reactions in women with breast cancer. This study aimed at investigating the amount of depression and its role in predicting the quality of life of women suffering from breast cancer. Materials and Methods: The present descriptive study in volved a correlation method with 98 women living in Kermanshah-Iran with breast cancer. According to the access to the patients and the condition of conducting the research, they were chosen by available sampling. Life quality inventory (World Health Organization, 1989) and depression inventory (Beck et al., 2000) were used to gather the data. Moreover, to analyze the relationships among the variables correlation analysis with Pearson method, as well as multiple regression with the enter method and frequency analysis were applied. Results: The findings revealed that not only is depression high, but also there is a negative significant relationship between depression and the quality of life, with predictive potential. Conclusions: The finding of a relationship between depression and the quality of life points to the need for addressing psychological problems of the affected individuals more appropriately. It is suggested that we consider psychological and educational services for patients in treatment planning to make people aware of different psychological aspects of their disease and ways of struggling and overcoming the problems.