 The purpose of this study was two-fold: i to assess whether MBSR favorably influences psychological status, quality of life, stress hormones, and immune status in breast cancer survivors; and ii to explore possible mechanisms by which MBSR may favorably influence these outcomes, in particular, through reduction in fear of breast cancer recurrence and associated perceived stress. Both objectives were studied at the critical transition time immediately following completion of surgical, radiation andor chemotherapy therapy for breast cancer. 