To define the prevalence of anti-Leptospira sp. agglutinins in ewes in the Federal District, Brazil, serum samples from 157 ewes were tested for antibodies against serovars of Leptospira sp. by the microscopic agglutination test. Antibodies were detected in three flocks in a prevalence of 3% (95% CI = 0.4%-5.7%). Considering that sheep and cattle were raised together, the lack of sanitary control could represent a risk to cattle production, which is the most important activity in the Centre-West region of Brazil.