The aim of the current study is to evaluate the epidemiological aspects of leptospirosis in cattle herds from indigenous reserves. Serum samples from cows-not vaccinated against the disease and distributed in five indigenous reserves of Barra do Corda region, Maranhão State-were subjected to the microscopic agglutination technique. An epidemiological questionnaire focused on investigating the risk factors associated with Leptospira spp. infection was applied in each indigenous reserve. Of the 300 analyzed samples, 80% presented positive reactions with titers equal to or higher than 1:100. Reactive animals were identified in all (100%) indigenous reserves. The most often found serovars of the Leptospira spp. complex are herein presented in descending order: