Objective: To examine whether mindfulness-based cognitive therapy (MBCT) increases momentary positive emotions and the ability to make use of natural rewards in daily life. Method: Adults with a life-time history of depression and current residual depressive symptoms (mean age = 43.9 years, SD = 9.6; 75% female; all Caucasian) were randomized to MBCT (n = 64) or waitlist control (CONTROL; n = 66) in a parallel, open-label, randomized controlled trial. The Experience Sampling Method was used to measure momentary positive emotions as well as appraisal of pleasant activities in daily life during 6 days before and after the intervention. Residual depressive symptoms were measured using the 17-item Hamilton Depression Rating Scale (Hamilton, 1960). Results: MBCT compared to CONTROL was associated with significant increases in appraisals of positive emotion (b* = 0.39) and activity pleasantness (b* = 0.22) as well as enhanced ability to boost momentary positive emotions by engaging in pleasant activities (b* = 0.08; all ps less than 0.005). Associations remained significant when corrected for reductions in depressive symptoms or for reductions in negative emotion, rumination, and worry. In the MBCT condition, increases in positive emotion variables were associated with reduction of residual depressive symptoms (all ps less than 0.05). Conclusions: MBCT is associated with increased experience of momentary positive emotions as well as greater appreciation of, and enhanced responsiveness to, pleasant daily-life activities. These changes were unlikely to be pure epiphenomena of decreased depression and, given the role of positive emotions in resilience against depression, may contribute to the protective effects of MBCT against depressive relapse. (Contains 1 footnote, 2 tables, and 3 figures.)