Cases of leptospirosis in Indonesia increased dramatically in 2018 by 895 cases with 148 death cases due to leptospirosis in 2018. Risk factors were found in more than half of leptospirosis events including environmental conditions, the presence of rodents, waste water disposal, waste disposal facilities, history of contact with rats, presence of rivers, and history of flooding. Previous research has reported the finding of mice containing Leptospira in post-flood areas in Indonesia. Therefore this study aimed to determine the relationship of environmental conditions with the presence of Leptospira bacteria in rats in flood-prone areas. This research is an analytic study with cross sectional approach. Data obtained by observing the type of rat, the process of surgery and taking rats, rats calculation of success traps and observation of environmental conditions. The polymerase chain reaction (PCR) test was carried out in the Microbiology Laboratory of Hasanuddin University Hospital. Statistical tests with fisher exact were used to determine the relationship of environmental conditions with the presence of Leptospira bacteria in rats. The results of this study found 100% Mus musculus, 53.3% Rattus norvegicus, 22.2% Rattus tanezumi infected with Leptospira bacteria. The results showed the presence of sewers with stagnant water (0,000), presence of standing water other than sewers (0,026), presence of sewage waste (0,005), presence of waste other than ditches (0,007), smell of rat urine (0,049) and pH of stagnant water the optimum (0.001) with a p-value < 0,05. We recommend to the Paccerakkang inhabitants who reside in flood-prone areas, to always maintain environmental conditions such as cleaning the environment suspected of being a habitat for rats.