Background: The observations that smokers with chronic obstructive pulmonary disease (COPD) are at increased risk of depression and that nicotine may have antidepressant effects and regulate mood provide a rationale for the use of antidepressant drugs for smoking cessation in patients with COPD. No clinical trial has studied the efficacy of bupropion hydrochloride and nortriptyline hydrochloride for smoking cessation in this patient population, to our knowledge. Methods: In a placebo-controlled double-dummy randomized trial, 255 adults at risk for COPD or with COPD were prescribed sustained-release bupropion (bupropion SR) (150 Ing twice daily) or nortriptyline (75 mg once daily) for 12 weeks. All patients received smoking cessation counseling. The main outcome measure was prolonged abstinence from smoking from week 4 to week 26 after the target quit date. Results: The use of bupropion SR and nortriptyline sulted in higher prolonged abstinence rates compared with placebo, although only the difference between bupropion SR and placebo was statistically significant (differences with placebo, 13.1% [95% confidence interval, 1.2%-25.1%] for bupropion SR and 10.2% [95% confidence interval, -1.7% to 22.2%] for nortriptyline). Inpatients with COPD, bupropion SR and nortriptyline seem efficacious in achieving prolonged abstinence (differences with placebo, 18.9% [95% confidence interval, 3.6%-34.2%] for bupropion SR and 12.9% [95% confidence interval, -0.8% to 26.4%] for nortriptyline). In participants at risk for COPD, no statistically significant differences with placebo in prolonged abstinence rates were found. Conclusions: Bupropion SR treatment is an efficacious aid to smoking cessation in patients with COPD. Nortriptyline treatment seems to be a useful alternative.