BackgroundKnowledge of factors associated with TB mortality during treatment and post treatment will help us develop better monitoring and implementation strategies for TB control. We designed the present study to examine the factors associated with mortality in HIV‐TB co‐infected patients during and after the course of TB treatment.MethodsThis study is a cohort analysis of secondary data collected from 1804 HIV‐TB co‐infected individuals from 16 anti‐retroviral therapy (ART) centres affiliated with the Mumbai Districts AIDS Control Society, Mumbai, India. We used Kaplan Meier survival curves and hazard ratios to estimate the mortality in patients.ResultsThe overall mortality rate in this cohort was 1.14 per 100 per month. The mortality proportion was 18% (95% CI: 16.1%, 20.1%) during treatment and 10.6% (95% CI: 8.9%, 12.5%) in the post‐treatment period. Mortality was significantly higher in those with a CD4 count 0–200 cells/mm3 (HR: 3.04, 95% CI: 2.13, 4.15; p < 0.001), and in patients who were ART naïve and referred to the ART centre with a diagnosis of TB (HR: 1.39, 95% CI: 1.06, 1.82; p = 0.016). Mortality was also significantly higher in the first 6 months after initiation of ART (HR: 1.36, 95% CI: 1.06, 1.75; p = 0.016). A decrease in the CD4 counts from initial levels at start of TB treatment to end of TB treatment was associated with higher mortality in the post‐treatment period.DiscussionThe overall mortality remains high; early identification of TB and HIV disease, and use of rapid point of care tests for diagnosis of TB are needed across all health care facilities. Post‐treatment follow‐up and monitoring is important in HIV‐TB co‐infected patients, and post‐treatment mortality should also be considered as one of the indicators for successful TB control programmes.