OBJECTIVE: In India, 50%-80% of patients with tuberculosis (TB) seek private care. This study set out to explore HIV testing and referral practices of private hospital doctors treating patients with TB. METHODS: Interviews were conducted with private hospital doctors (n = 15). Interviews covered HIV testing, linking HIV-positive patients with TB to HIV care, and coordination of care for co-infected patients. RESULTS: Doctors did not routinely refer patients with TB to government HIV testing facilities as per national policy guidance. If deemed appropriate, then testing was conducted privately. Testing was more common when a facility guideline mandated testing or a public-private initiative for TB management was in place. Otherwise, testing was based on doctors' judgement. Patients accustomed to private care who could not afford treatment were reportedly reluctant to shift to public facilities. A lack of communication between public and private doctors was found to undermine co-management. CONCLUSIONS: In this sample, private provider practices were influenced by both the social and the health systems contexts in which they operated. An understanding of patient perceptions of HIV, private doctors concerns for retaining patients, and the contrasting philosophies of private medicine versus public health objectives was found to be critical to explain HIV testing and referral behaviours. The government has proposed to scale up HIV testing and treatment among patients with TB, yet operationalising this will require engagement with the realities of a large, diverse private sector. It will also require considering what role government policies can have on shaping private practice and how to potentially integrate public and private care.