SETTING: Seventeen health care facilities that report to the national tuberculosis (TB) programme in Timor-Leste. Participants were TB patients.OBJECTIVE: To determine the proportion of TB patients who experienced catastrophic costs due to their TB diagnosis and care, and the magnitude and composition of these costs.DESIGN: This was a cross-sectional health facility-based survey, conducted in 17 DOTS centres between October 2016 and March 2017. TB patients were interviewed by trained nurses using a standardised questionnaire.RESULTS: Among the 457 TB patients who participated (response rate 96.6%), the median age was 32 years; 39.2% were from the capital, Dili. The patient was the main income earner in 26.3% of households. Annual individual and household incomes before and after TB diagnosis decreased by respectively 30.4% and 31.1%. Using a cut-off of 20% of annual household income, 83.0% of patients experienced catastrophic costs related to their TB diagnosis and care. Income loss and nutritional supplementation accounted for respectively 40.7% and 37.9% of these costs.CONCLUSION: Four of five TB patients in Timor-Leste experienced catastrophic costs related to TB diagnosis and care. Financial and social protection to mitigate against these costs are urgently needed, in addition to universal health coverage.