Abstract Objectives: Patients with chronic obstructive lung disease (COPD) suffer from significant dyspnea and may benefit from complementary and alternative medicine (CAM) therapies aimed at mitigating symptoms. The objective of this study was to test the efficacy of a mindfulness-based breathing therapy (MBBT) on improving symptoms and health-related quality of life in those with COPD. Design: We conducted a randomized controlled trial of 8-week mindfulness-based breathing therapy (MBBT) compared to support groups to test efficacy on improving symptoms and health-related quality of life in those with COPD. Setting: The setting for this study was an academic-affiliated veterans healthcare system. Subjects: The subjects consisted of 86 patients with COPD. Interventions: MBBT included weekly meetings practicing mindfulness mediation and relaxation response. Outcome measures: The main outcome measure was a post 6-minute-walk test (6MWT) Borg dyspnea assessment. Other outcome measures included health-related quality of life measures, 6MWT distance, symptom scores, exacerbation rates, and measures of stress and mindfulness. Analysis of covariance compared differences in outcomes between groups; paired t test evaluated changes within groups. Results: Participants were predominantly elderly men with moderate to severe COPD. We found no improvements in dyspnea (post 6MWT Borg difference between the MBBT and support group was 0.3 (95% confidence interval [CI]: À