['To determine risk factors for poor outcomes among patients with pulmonary multidrug- or extensively drug-resistant (M/XDR) tuberculosis (TB) in Georgia.', 'This was a prospective, population-based observational cohort study.', 'Among 380M/XDR-TB patients (mean age 38 years), 179 (47%) had a poor outcome: 59 (16%) died, 37 (10%) failed, and 83 (22%) defaulted. Newly diagnosed M/XDR-TB cases were significantly more likely to have a favorable outcome than retreatment cases (odds ratio (OR) 4.26, 95% confidence interval (CI) 1.99-9.10, p<0.001). In the multivariable analysis, independent risk factors for a poor treatment outcome included previous treatment history (OR 2.92, 95% CI 1.29-6.58), bilateral disease (OR 1.90, 95% CI 1.20-3.01), body mass index (BMI, kg/m(2)) ≤18.5 (OR 1.91, 95% CI 1.11-3.29), and XDR-TB (OR 2.28, 95% CI 1.11-4.71). Patients who underwent surgical resection (OR 0.27, 95% CI 0.11-0.64) and had sputum culture conversion by 4 months (OR 0.33, 95% CI 0.21-0.52) were significantly less likely to have poor treatment outcomes.'] Does adjunctive surgery improve treatment outcomes among patients with multidrug-resistant and extensively drug-resistant tuberculosis?