The current review presents up-to-date knowledge on tuberculosis (TB) in diabetic patients. On the basis of available literature, there is little doubt about the close relationship between these two conditions. Diabetes mellitus in this association may still contribute substantially to the burden of TB and negatively affect control of the latter. Chronic hyperglycemia at least to some extent may alter the clinical manifestation, radiological appearance, treatment outcome and prognosis of TB. Although the pathogenesis is not clear, diabetes may impair both innate and adaptive immune responses to Mycobacterium tuberculosis. Eventually, effective screening and dual management of the diseases have to be addressed both in low- and high-income countries in order to limit the negative effects of the forthcoming global diabetes epidemic.