Agricultural activities expose workers to biological risk, due to the close contact that could occur with pathogens' reservoirs, such as soil, animals, manure and animal products. The paper describes factors that have contributed on the reduction or eradication of zoonoses, such as brucellosis, salmonellosis and bovine tuberculosis (monitoring and prevention of animal infectious diseases, industrialization and mechanization of agricultural activities), and on the other hand the emergence of new risks and new diseases (adaptability of microorganisms, generation of new strains, antibiotic resistance, dissemination of vectors). The role of Occupational Medicine in the prevention of zoonoses is discussed.