INTRODUCTION : Floods represent the most prevalent natural calamities globally, with their impact expected to amplify due to the influences of climate change and population displacement. In December 2023, Tamil Nadu faced substantial rainfall, notably in Chennai and its suburbs and in Southern Districts of Tamil Nadu namely Thoothukudi, Tirunelveli, Tenkasi and Kanniyakumari, triggering extensive flooding. This paper endeavours to document the lessons learned from Tamil Nadu's flood response in 2023 and the subsequent measures being undertaken by the public health system to enhance preparedness. The various Public Health interventions implemented to address potential outbreaks following a disaster, included establishment of incident command system at State and District level; establishment of a helpline number for immediate assistance; continuous Disease Surveillance; risk stratification of areas; formation of task-specific teams to address different aspects of the emergency and continuous monitoring of activities. The flood response activity in Tamil Nadu has demonstrated remarkable effectiveness, as evidenced by the absence of any outbreaks in both Chennai and the southern districts, which were affected by flood.