Within a randomized, waitlist-controlled study of Mindfulness-Based Stress Reduction (MBSR) among rheumatoid arthritis patients, we evaluated treatment effect on immune parameters c-reactive protein (CRP), interleukin(IL)-6, IL-10 and transforming growth factor-beta-1 (TGF), the relation between depressive symptoms and well-being and immune parameters, and relation to meditation practice. 63 patients were randomized to 8-week MBSR or control. Assessments at baseline, 2-months (2M), 6-months (6M) included depressive symptoms (SCL-90) and well-being (PWBS). Blood samples were analyzed by ELISA. Practice time was hours of sitting meditation. Immune data were log-transformed and back-transformed post-analysis. Repeated-measures mixed-models were employed to evaluate treatment effect on immune parameters, relation between depressive symptoms/well-being and immune parameters, and association between meditation and immune parameters (latter MBSR only). No statistically significant treatment effect of MBSR on immune parameters was observed. Collapsing treatment groups, changes in depressive symptoms were associated with changes in TGF such that decrease of 1.0 in depressive symptoms was associated with 26% increase in TGF at 2M (p=0.04). Well-being was associated with CRP, such that 10-point improvement in well-being was associated with 8% decrease in CRP at 2M (p=0.04). In MBSR, meditation was associated with significant decrease in CRP and marginally significant decrease in IL-6. On average, 1 hour of meditation practice at home was associated with 6% decrease in CRP (p=0.03) and 7% decrease in IL6 (p=0.08) by 2M. No treatment effect of MBSR on CRP, IL-6, IL-10 or TGF was observed. Collapsing treatment groups, improvements in depressive symptoms and well-being were associated with improved TGF and CRP, suggesting enhanced emotional status is associated with immune response prospectively. Sitting meditation may be helpful to improve CRP and IL-6, pro-inflammatory factors associated with depression. Larger studies may clarify the relation between meditation and pro-inflammatory immune parameters.