Mindfulness-Based Stress Reduction (MBSR) is a program that has been shown to be beneficial for clinical and non-clinical populations. While much attention has been paid to participants' outcomes, little work has been published concerning processes underlying improvements. Herein, women who had finished medical treatment for breast cancer completed questionnaires pre- and post-MBSR and were interviewed using focus group methodology such that quantitative and qualitative data were combined to explore potential mechanisms underlying changes. It was found that the Mindfulness Attention Awareness Scale was a useful process measure to assess changes in mindfulness and that the Coping with Health Injuries and Problems questionnaire was useful in documenting changes in palliative (self-care) coping over the course of the 8 week program. Moreover, the Sense of Coherence questionnaire suggested that the women viewed life as more meaningful and manageable following MSBR. Our findings fit with Shapiro et al.'s theory that, over time, participants in an MBSR program "reperceive" what they encounter in their daily experiences.