Over the past decade, global and national tuberculosis (TB)-control programs, challenged with limited resources, have had to prioritize interventions to maximize impact. For this reason, patients with newly diagnosed cases of TB received more attention than did patients with a previous history of treatment. The recently launched STOP TB Strategy and Global Plan to STOP TB 2006-2015 now promote proper diagnosis and treatment of TB for all patients, without distinction of smear status, drug susceptibility, sex, or age, including all patients with a history of previous treatment. Previously treated patients are difficult to re-treat and represent an important source of disease transmission, as well as a serious threat to TB control worldwide, because of their higher rate of drug resistance.