The aim of the study was to determine the possible risk of the leptospiral transmission from animals to humans. 457 humans (both men and women) were divided into 2 groups: 1) of possible high risk infection consisted of people dealing as farm workers with cattle and pigs 2) of possible low risk infection consisted of people selected randomly. The animals on the farms were previously tested and found positive. All sera were examined using micro-agglutination test (MAT) with a battery of 18 serovars. The statistical evaluation of the results was performed using chi 2 test. The infection rate in I group was 13.79% and in II group was 1.5%. (p < or = 0.001). Sera of I group reacted with 7 serovars (sejroe, bratislava, canicola, tarassovi, bataviae, celledoni, patoc) and of II with 3 (hebdomadis, sejroe, hardjo). The infection rate in the group I was over 9 times higher than in group II. Thus dealing with infected animals is a high risk factor.