Type 2 diabetes mellitus is one of the leading causes of end-stage renal disease in the Western world. Smoking can also be seen as a powerful agent, although often underrated, able to induce renal damage and microvascular dysfunction via several different mechanisms, which often overlap with those of diabetic disease, and in concert may eventually worsen the renal redox homeostasis. As a result of this, the association of diabetes with smoking may favor the onset and/or the progression of renal insufficiency toward renal failure, and such a conclusion is supported by an array of epidemiological and physiopathological studies. Consequently, smoking prevention and cessation programs must be strongly encouraged not only to reduce the cardiovascular risk, but also to avoid the deterioration of renal function among diabetic patients.