Smoking has been determined as a cause of chronic obstructive pulmonary disease (COPD) in most patients. Smoking cessation should be stressed above everything else for COPD patients under all conditions. A smoking habit is determined not as a preference but as a dependency on tobacco; therefore, smoking cessation is difficult solely based on one's motivation. Smoking cessation therapy is employed with cessation aids. Now, we can use nicotine-containing gum, patches, and the nicotine-receptor partial agonist varenicline. First, nicotine from tobacco is replaced with a nicotin patch, or a nicotine-free condition is induced by varenicline. Subsequently, the drugs are gradually reduced. In Japan, smoking cessation therapy is covered by public health insurance as definite requirements.