Diabetes is one of the most common metabolic disorders and emerges secondary to an interaction between genetic, environmental and lifestyle factors. This work provides an overview of the impact of smoking on the development of vascular complications in this condition and also provides an overview of the potential role of smoking in predisposition to diabetes. There are many studies documenting the impact of smoking on health (not focused on patients with diabetes), suggesting that the health exposure in these individuals is at least comparable to that observed in the general population. Distinct studies of smoking in patients with diabetes have unambiguously confirmed an increased prevalence and a higher risk of early death associated with the development of macrovascular complications. Smoking is also associated with premature development of microvascular complications and may contribute to the pathogenesis of type 2 diabetes. It has been shown that smoking is a predictor of the progression of glucose intolerance at both the transition from normoglycaemia to impaired glucose tolerance status and the increased risk of developing diabetes. The mechanisms explaining the relationship between smoking and the development of diabetes are not fully understood, although a number of hypotheses have been put forward. Current evidence indicates that smoking cessation is not only important to prevent macrovascular complications in diabetes, but also has a role in limiting microvascular disease and may also facilitate glycaemic management in this condition.