Occupational inhalation of organic dust may be a cause of numerous symptoms and diseases. Organic dust consists of various biological compounds which induce inflammatory reactions in the lungs on an immunotoxic or allergic basis. Bacteria and their metabolites, moulds and their spores, mycotoxins, glucans, and other still unidentified substances, can be potential aetiologic factors of diseases caused by organic dust. The aim of this study was to determine the concentration and composition of airborne microflora in typical Polish swine buildings and to assess the health conditions of the workers employed within them. Total concentration of microorganisms in the air of five examined swine breeding farms ranged from 613.7-1246.7 x 10³ cfu/m³ (mean value 930.6 x 10³ cfu/ m³).The examination of 53 employees working in the swine buildings included their medical history, physical examination, spirometry, and allergological tests. Work-related symptoms were reported by 31 (58.5%) of the subjects. No abnormal findings were present upon physical and spirometric examinations. The results suggest the common occurrence of work-related respiratory disease in swine workers, mostly corresponding to the Organic Dust Toxic Syndrome (ODTS).