The purpose of this study was to examine relationships among self-blame for developing breast cancer, a self-forgiving attitude, mood, and quality of life among women with breast cancer. In this cross-sectional study, 123 women with Stages 0-III breast cancer completed questionnaires measuring demographic and medical characteristics, self-blame, self-forgiveness, mood, and quality of life. Women who blamed themselves reported more mood disturbance (p <or= .001) and poorer quality of life (p < .001) than those who did not blame themselves. Mediational analyses revealed that self-blame for cancer partially mediated the relationships between a self-forgiving attitude and both mood disturbance and quality of life (Z = -2.72, p = .006 and Z = -2.89, p = .004, respectively). Patients may benefit from a discussion with their oncologists and other healthcare providers about self-forgiveness and the potential benefits of reducing self-blame to facilitate adjustment to breast cancer.