BackgroundTuberculosis remains a major public health problem in sub-Saharan Africa. District hospitals (DHs) play a central role in district-based health systems, and their relation with vertical programmes is very important. Studies on the impact of vertical programmes on DHs are rare. This study aims to fill this gap. Its purpose is to analyse the interaction between the National Tuberculosis Control Programme (NTCP) and DHs in Cameroon, especially its effects on the human resources, routine health information system (HIS) and technical capacity at the hospital level.MethodsWe used a multiple case study methodology. From the Adamaoua Region, we selected two DHs, one public and one faith-based. We collected qualitative and quantitative data through document reviews, semi-structured interviews with district and regional staff, and observations in the two DHs.ResultsThe NTCP trained and supervised staff, designed and provided tuberculosis data collection and reporting tools, and provided anti-tuberculosis drugs, reagents and microscopes to DHs. However, these interventions were limited to the hospital units designated as Tuberculosis Diagnostic and Treatment Centres and to staff dedicated to tuberculosis control activities. The NTCP installed a parallel HIS that bypassed the District Health Services. The DH that performs well in terms of general hospital care and that is well managed was successful in tuberculosis control. Based on the available resources, the two hospitals adapt the organisation of tuberculosis control to their settings. The management teams in charge of the District Health Services are not involved in tuberculosis control. In our study, we identified several opportunities to strengthen the local health system that have been missed by the NTCP and the health system managers.ConclusionWell-managed DHs perform better in terms of tuberculosis control than DHs that are not well managed. The analysis of the effects of the NTCP on the human resources, HIS and technical capacity of DHs indicates that the NTCP supports, rather than strengthens, the local health system. Moreover, there is potential for this support to be enhanced. Positive synergies between the NTCP and district health systems can be achieved if opportunities to strengthen the district health system are seized. The question remains, however, of why managers do not take advantage of the opportunities to strengthen the health system.