Pre-operative smoking cessation is a must for successful surgery! Pulmonary resection has a certain mortality rate, but the chance of dying directly from surgery and anesthesia is very low, generally considered to be below 1%. The common cause of death is postoperative complications, of which postoperative pneumonia is the most common and leading cause of death, and the occurrence of postoperative pneumonia is strongly related to continued smoking prior to surgery. Postoperative cardiopulmonary failure is another major cause of death, and preoperative smoking is one of the major causes of lung function abnormalities that eventually lead to cardiopulmonary failure. Therefore, the first prescription for lung cancer doctors, especially pulmonary surgeons, is to “quit smoking”. It is usually required to quit smoking for more than 3 weeks before surgery. Quitting smoking is by far the simplest, most direct and definitive way to prevent lung cancer. Most methods used for adults do not work in younger generations, and most young people believe that cancer is not a disease of their age. The incidence of lung cancer decreases significantly after 10 years of cessation, to about half that of continuing smokers, but the incidence of lung cancer is still high within 10 years of cessation. Heavy smokers have a much higher chance of developing lung cancer than nonsmokers, although nonsmokers can also develop lung cancer. The criterion for heavy smoking is 20 years, i.e., one pack per day for 20 years, or two packs per day for 10 years. Studies show that only up to 10-15% of heavy smokers eventually develop lung cancer. However, this does not mean that they do not die from smoking. On the contrary, in addition to lung cancer, heavy smokers also die from other smoking-related diseases, such as: chronic obstructive pulmonary disease, peripheral vascular disease, coronary heart disease, etc. There is no evidence that the so-called safe cigarettes have a carcinogenic effect. It is currently believed that nonsmokers should have a small chance of developing lung cancer, and the cause of nonsmoking lung cancer, called spontaneous lung cancer, which commonly occurs in young women with alveolar cell carcinoma, is unknown. Environmental smokers can cause lung cancer, and are most affected by children living in homes with heavy-smoking parents and nonsmokers who work in closed environments where their co-workers are heavy smokers. However, the specific effect of passive smoking on the development of lung cancer is inconclusive. There is no evidence that incidental passive smoking in public places or restaurants increases lung cancer. Work environments such as asbestos and radon exposure can promote lung cancer.