Some studies have shown that smoking in diabetic patients may lead to elevated blood glucose. An epidemiological survey among Chinese men with type 2 diabetes showed that both fasting blood glucose and glycosylated hemoglobin tended to increase with increased smoking. This shows that smoking in diabetic patients may lead to elevated blood glucose. It is recommended that all people with diabetes refrain from smoking and using other tobacco-based products and e-cigarettes, and minimize exposure to secondhand smoke. Smoking is not only an important risk factor for cancer, respiratory and cardiovascular diseases, but is also closely related to the development of diabetes and its complications. Diabetic patients should quit smoking, pay attention to a low-salt, low-fat, low-sugar diet, monitor their blood glucose, take their medications on time, and actively control their blood glucose.