SETTING Drug-resistant tuberculosis (TB) is an important public health problem in Latvia. OBJECTIVE To document trends, characteristics and treatment outcomes of registered patients with multi-drug-resistant (MDR-) and extensively drug-resistant (XDR-) TB in Latvia from 2000 to 2010. DESIGN A retrospective national cohort study. RESULTS Of 1779 patients, 1646 (92%) had MDR- and 133 (8%) XDR-TB. Over 11 years, the proportion of XDR-TB among MDR-TB patients increased from 2% to 18%. Compared to MDR-TB patients, those with XDR-TB were significantly more likely to have failed MDR-TB treatment (OR 8.4, 95%CI 4.3-16.2), have human immunodeficiency virus infection (OR 3.2, 95%CI 1.8-5.7), be illegal drug users (OR 5.7, 95%CI 2.6-11.6) or have had contact with MDR-TB patients (OR 1.9, 95%CI 1.3-2.8). Cure rates for XDR-TB were 50%. Compared with MDR-TB patients, those with XDR-TB had a higher risk of treatment failure (29% vs. 8%, respectively, P < 0.001). Unfavourable treatment outcomes were significantly associated with being male; having smear-positive disease; pulmonary cavities; failure, default or relapse after previous MDR-TB treatment; and a history of incarceration. CONCLUSION More MDR-TB in Latvia is now also XDR-TB. This study identified several risk factors for XDR-TB and, for unfavourable treatment outcomes, highlighting the importance of early diagnosis and appropriate management of MDR-/XDR-TB.