Breast cancer is the most common type of cancer among women that creates stress in physical, mental, and spiritual aspects of patients’ life. Adjustment consequences for these patients may lead to posttraumatic growth. Given the impacts of spirituality on posttraumatic growth, the present study aimed to examine the role of religious coping in predicting posttraumatic growth among patients with breast cancer. This was a descriptive-correlational study. The study population included all 121 participants with breast cancer who referred to treatment centers. The sample consisted of 121 patients whom were selected through convenience sampling method. Variables were evaluated using religious coping style and the posttraumatic growth inventory. Findings indicated that dimensions of active religious activities, benevolent evaluation, and religious activities (dimensions of positive religious coping) were positively correlated with posttraumatic growth and these relationships were significant at the 0.99 confidence level. The results of regression analysis, conducted to predict posttraumatic growth, demonstrated that in the first step, benevolent evaluation (0.39) predicted the posttraumatic growth. Thus according to the results, benevolent evaluation can predict posttraumatic growth (Beta=0.63). Based on the study findings, it is recommended to pay attention to positive religious coping as a strategy to achieve posttraumatic growth in patients with cancer.