Smoking in small amounts is not recommended for people with diabetes, and it is best to quit smoking. All people with diabetes are advised to refrain from smoking and the use of other tobacco-based products and e-cigarettes, and to minimize exposure to second-hand smoke. Smoking is not only an important risk factor for cancer, respiratory and cardiovascular diseases, but is also closely associated with the development of diabetes and its complications. Smoking also increases the risk of various complications of diabetes, especially macrovascular disease. Smoking can also damage the structure and function of glomeruli, increasing the occurrence of urinary protein and diabetic nephropathy. Smoking cessation significantly reduces the incidence of cardiovascular disease and all-cause mortality. Smoking cessation also slows the progression of diabetic nephropathy. Smoking cessation increases HDL cholesterol levels and decreases LDL cholesterol, thus contributing to the prevention of diabetic complications. People with diabetes should quit smoking under the guidance of a medical professional.