BACKGROUND: TB in low-incidence countries is characterised by changes in age distribution towards larger numbers of cases among the elderly.OBJECTIVES: To investigate clinical features and outcomes of TB treatment in older patients and identify predictors of poor outcome.METHODS: Multicentre retrospective study of new TB cases from 53 hospitals included in the registry of the Integrated Tuberculosis Research Programme of the Spanish Society of Pulmonology and Thoracic Surgery (Sociedad Española de Neumología y Cirugía Torácica) between 2006 and 2020.RESULTS: We identified 731 patients aged ≥75 years from a cohort of 7,505 patients with TB. In the elderly, weight loss, disseminated disease and normal X-rays or infiltrates without cavitation were more common. All-cause mortality was 16% (5% of deaths due to TB). The elderly had higher rates of toxicity (6.7%) and hospital admissions (36%). In the multivariate analysis of predictors of TB mortality in ≥75-year-olds, only weight, age and treatment with non-standard regimens remained significant.CONCLUSIONS: TB in older patients needs more attention and remains a challenge because of a lack of specific clinical and radiological features. Standard treatment is effective, although mortality is higher than in young patients. Low weight, non-standard regimens and age are significant predictors of TB mortality.