Purpose: Herbal medicines are commonly used by people with chronic obstructive pulmonary disease (COPD) but high quality randomized controlled trials are limited. This study evaluated the therapeutic value of ginseng capsules in reducing acute exacerbations and improving the quality of life in people with COPD. Patients and Methods: This randomized, double-blind and placebo-controlled trial assessed ginseng's effects on 200 patients with moderate to very severe COPD. Ginseng capsules (200 mg, twice per day) were compared to placebo over 24 weeks. Patients were followed up for a further 24 weeks after the treatment period. The primary outcome measure was acute COPD exacerbation rate over 12 months. Secondary outcome measures were health-related quality of life, including the St George's Respiratory Questionnaire (SGRQ), COPD Assessment Test (CAT) and the Short Form 36 Health Survey (SF-36). We also assessed lung function, walking distance and use of relief medication. Results: Baseline characteristics were balanced between groups. The rate of COPD exacerbations was not statistically significant between groups after 1 year (62 participants in the ginseng group and 63 in the placebo group). Secondary outcome measures showed improvements after ginseng and placebo but results were not clinically significant. The incidence of adverse events in the two groups was similar and events were unrelated to the intervention. Conclusion: Compared with placebo, ginseng did not reduce the rate of acute COPD exacerbations over 12 months. It was safe and well tolerated by people with moderate to very severe COPD.