Setting: Two tertiary care hospitals and 12 peripheral health institutions (PHIs) in Trivandrum, Kerala, India. Objective: To determine factors associated with the prevalence of diabetes mellitus (DM) among tuberculosis (TB) patients and examine differences in the proportion of new DM cases among TB patients diagnosed at tertiary care centres and PHIs. Design: A descriptive study: TB patients diagnosed during March-September 2012 were screened for known DM. Those with unknown DM status were tested for random blood glucose and fasting blood glucose (FBG); FBG ⩾ 126 mg/dl was diagnosed as new DM. Results: Of 920 TB patients, 689 (72%) were male and the mean (standard deviation) age was 47.6 (16.4) years. Of these, 298 (32.4%) were diabetic: 235 (26%) had previously known DM and 63 (7%) were newly diagnosed. During the screening at PHIs and tertiary care hospitals, respectively 30/183 (16.4%) and 33/737 (4.5%) were newly diagnosed with DM (OR 3.71; 95%CI 2.17-6.32). Overall, age >50 years and pulmonary tuberculosis were independently associated with a higher prevalence of diabetes. Conclusion: As nearly one in three TB patients had DM, we recommend that TB patients should be routinely screened for DM in Kerala. As the proportion of new DM was higher among TB patients diagnosed at PHIs, we would recommend that specific attention and investment be directed to PHIs. India, the country with the highest number of tuberculosis (TB) cases in the world (an estimated 2.2 million cases in 2011), 1 also has a very high burden of diabetes mellitus (DM), with an estimated 63 million cases in 2012. 2 In India, 15% of pulmonary tuberculosis (PTB) cases have been estimated to be attributable to DM. 3 DM also affects TB treatment outcomes and may delay sputum conversion, increase case fatality rates during treatment, lead to increased failure rates in non-drug-resistant cases and also increase relapse rates of TB after successful completion of treatment. 4,5 Given this scenario, it has been felt that active screening for DM in TB patients may allow identifi cation of previously undiagnosed DM and improve TB treatment outcomes through improved DM care.Diabetes is common in Kerala, a state in South India with a population of 34.6 million, with an estimated community prevalence of 16-20%. 6 TB patients, with a recent study reporting a prevalence of 44%. 9 As standardised procedures for DM screening among TB patients for use in hospitals and TB units (TUs)-a sub-district level tuberculosis programme management unit covering a population of 500 000, made up of varying numbers of peripheral health institutions (PHIs)-were not available in India, a monitoring tool linked to the TB registration and quarterly reporting system was developed and implemented, starting in multiple centres in India in 2012. The fi ndings of this pilot study 10 showed that the screening procedures worked well, and the overall prevalence of DM in over 8000 screened TB patients was 13%. Trivandrum, in Kerala, was one of the sites that implemented screening at both ...