The impact of microscopic fungi on the farmers' health seems to be underestimated. In the present article an overview of fungi as pathogens is presented with reference to occupational hygiene in agriculture and related areas. The infection may be transmitted from infected humans, animals, plants or soil. To date, little epidemiological data on fungal skin disease in farmers is available. Epidemiological studies from Poland suggest that mycoses are the most prevalent skin diseases in farmers, and may be present even in over 20% of the population. Working conditions on farms greatly enhance the development of fungal infections. Farmers spend most of their working time in humid conditions, wearing rubber boots for long hours, etc. Another professional groups at higher risk for developing a fungal disease are animal feeders, foresters, grave-diggers and veterinarians as well as employees working in the food industry. Besides infection, fungi may also cause non-invasive forms of skin disease, as dermato-mycotoxicosis professionalis or alternariosis. Criteria for classifying a case of mycosis as occupational disease are also discussed.