With the mounting evidence for mindfulness training as a promising strategy for distress reduction across clinical and nonclinical populations, it is important to learn more about the kinds of changes associated with this training. In an exposure-based cognitive therapy for depression that includes mindfulness training, participants reported significant increases in mindfulness over the course of therapy. Hierarchical linear modeling revealed that change in mindfulness was associated with a linear decrease in depression on self-report and clinical interview measures over the course of therapy. Increases in mindfulness were significantly correlated with reductions in avoidance and rumination, two emotion regulation strategies that are conceptual opposites of mindfulness.