BACKGROUND: In recent years, there has been increased recognition of the need to integrate mental health services into routine tuberculosis (TB) care. For successful integration, policymakers need to first understand the practices of TB health workers in the management of mental health conditions, including depression, anxiety, and psychological distress, and use this to decide how best mental health services could be delivered in tandem with TB services. In this qualitative study we aimed to understand how TB health workers and other stakeholders viewed mental health conditions linked to TB and how they screened and treated these in their patients. METHODS: The study draws on qualitative data collected in 2018 as part of the Tuberculosis Reduction through Expanded Antiretroviral Treatment and Screening for active TB trial (TREATS), conducted in eight urban communities in Zambia. Data were collected through 17 focus group discussions with local health committee members (n = 96) and TB stakeholders (n = 57) present in the communities. Further in-depth interviews were held with key TB health workers (n = 9). Thematic analysis was conducted. RESULTS: TB stakeholders and health workers had an inadequate understanding of mental health and commonly described mental health conditions among TB patients by using stigmatizing terminology and overtones, for example "madness", which often implied a characterological flaw rather an actual illness. Psychological distress was also described as "overthinking", which participants attributed to psychosocial stressors, and was not perceived as a condition that would benefit from mental health intervention. There were no standard screening and treatment options for mental health conditions in TB patients and most TB health workers had no mental health training. TB Stakeholders and health workers understood the negative implications of mental health conditions on TB treatment adherence and overall wellbeing for TB patients. CONCLUSIONS: TB stakeholders and health workers in Zambia have a complex conceptualisation of mental health and illness, that does not support the mental health needs of TB patients. The integration of mental health training in TB services could be beneficial and shift negative attitudes about mental health. Further, TB patients should be screened for mental health conditions and offered treatment. Trial registration number NCT03739736-Registered on the 14th of November 2018- Retrospectively registered- https://clinicaltrials.gov/ct2/results?cond=&term=NCT03739736&cntry=&state=&city=&dist.