Recent research has begun to distinguish between various aspects of self-report measures of mindfulness, including the distinction between mindful process and outcome. Therefore, our primary goal in this study was to examine whether an increase in mindful outcome mediated the relationship between an increase in mindful process and improvements in mental and physical health and perceived stress among mindfulness-based stress reduction (MBSR) participants. Consistent with expectations, we found that changes in mindful outcome partially mediated relationships between changes in mindful process and two outcomes: mental health and perceived stress (but not physical health). Moreover, as expected, in an alternate model, changes in mindful outcome did not facilitate changes in mindful process and improvements in any of the outcome variables. The implications and limitations of these findings, as well as recommendations for future research, are discussed.