Aim of the study was to detect antibodies and potential risk factors for an infec- tion with Leptospira in horses in Middle Germany. Serum samples of 314 horses were examined retrospectively by microscopic agglutination test for the presence of antibodies against eight Leptospira serovars. In total, 17.2% (n = 54) of the horses were positive for one or more of the serovars analyzed. The most prevalent serovar was lcterohaemorrhagiae (11.1%), followed by serovar Bratislava (9.6 %) and Grippotyphosa (1.9%). Mares showed a significantly higher occurrence of antibodies (p < 0.05) than geldings or stallions. Horses used for breeding have a significantly lower risk than horses used in sport or horses used for leisure activity. There was also a significantly higher prevalence (p < 0.05) in summer than in the other seasons. No significant influence of breed, husbandry conditions and age on the antibody occurrence was observed (p > 0.05). The clinical chemical parameters did not differ significantly between horses with positive or negative Leptospira antibody result (p > 0.05). It became apparent that horses can be infected with Leptospira without developing of clinical symptoms.