Objective To investigate the extent and associations of patient/diagnostic delay and other potential factors with catastrophic health expenditure (CHE) for tuberculosis (TB) care in Chongqing municipality, China.

Design A cross-sectional study.

Setting Four counties of Chongqing municipality, China.

Participants A total of 1199 patients with active pulmonary TB beyond 16 years and without mental disorders were consecutively recruited in the four counties’ designated TB medical institutions.

Outcome measures The incidence and intensity of CHE for TB care were described. The association between patients’ ‘sociodemographic and clinical characteristics such as patient delay, diagnostic delay, forms of TB, health insurance status and hospitalisation and CHE were analysed using univariate and multivariate logistic regression.

Results The incidence of CHE was 52.8% and out-of-pocket (OOP) payments were 93% of the total costs for TB care. Compared with patients without delay, the incidence and intensity of CHE were higher in patients who had patient delay or diagnostic delay. Patients who experienced patient delay or diagnostic delay, who was a male, elderly (≥60 years), an inhabitant, a peasant, divorced/widow, the New Cooperative Medical Scheme membership had greater risks of incurring CHE for TB care. Having a higher educational level appeared to be a protective factor. However, hospitalisation was not associated with CHE after controlling for other variables.

Conclusion The incidence and intensity of CHE for TB care are high, which provides baseline data about catastrophic costs that TB-related households faced in Chongqing of China. Variety of determinants of CHE implicate that it is essential to take effective measures to promote early seeking care and early diagnosis, improve the actual reimbursement rates of health insurance, especially for outpatients, and need more fine-tuned interventions such as precise poverty alleviation to reduce catastrophic costs of the vulnerable population.