The association between diabetes and incidence of tuberculosis is well established, and observational studies have shown poor treatment outcome in tuberculosis related to hyperglycemia. The WHO recommends screening for diabetes among all patients with tuberculosis and optimized glycemic control aiming at improving tuberculosis outcome. However, no intervention studies support this notion. Patients with tuberculosis are often vulnerable with high degree of comorbidity, and, therefore, at high risk of adverse effects of intensive glucose control. Controlled intervention studies of the effect of glucose lowering treatment on tuberculosis outcomes are clearly warranted to justify screening for- and tight control of diabetes.