Ensuring the successful treatment of tuberculosis (TB) is an essential public health responsibility of national TB programs. This case study describes how the Department of Health and Family Welfare, Kerala state, successfully prevented the disruptions in TB treatment when an unprecedented massive flood, declared as “a calamity of severe nature,” completely disrupted normal operations in the state during August 2018. Unanticipated floods led to the displacement and relocation of more than 1.5 million citizens. The state has ensured continuity of TB treatment for all notified drug sensitive and drug-resistant TB patients (9608 and 434, respectively), including those who were displaced and relocated. A real-time web-enabled, case-based patient management information system has helped preserve the entire patient information, available at multiple levels. Routine strength of the program, including good rapport with patients, frontline multipurpose health workers and treatment supporters, high literacy rate of general population, and well-integrated primary health care system delivering TB services, enabled ensuring continuity of care during the disaster situation. The success of the post-flood TB control measures in Kerala affirms the importance of maintaining an integrated and strong TB control component with general health system ownership.