Leptospirosis is a bacterial infection that spreads through water contaminated by the urine of infected animals, especially rodents. In India, cases surge every monsoon season as heavy rains, flooding, and poor drainage create ideal conditions for the bacteria to survive and spread. This article explains how leptospirosis spreads, why it is closely linked to the monsoon, who is most at risk, and what can be done to prevent and control outbreaks.