Farmers are known to be at high risk from the development of occupational airway disease. The first stage of the European farmers' study has shown that pig farmers in Denmark and Germany, poultry farmers in Switzerland and greenhouse workers in Spain were at highest risk for work-related respiratory symptoms. Therefore, the aim of this study was to determine exposure levels at relevant farm workplaces. Dust and endotoxin levels as well as microbiological concentrations were determined in 213 crop and animal farming environments by personal sampling. The highest total dust concentrations were found in poultry houses in Switzerland with median concentrations of 7.01 mg/m(3). The median airborne endotoxin concentrations in total dust ranged between 0.36 ng/m(3) in Spanish greenhouses and 257.58 ng/m(3) in poultry houses in Switzerland. Likewise, the highest median concentrations of total (2.0 x (7) cells/m(3)) and active fungi (4.4 x (5) cfu/m(3)) have been found in Swiss poultry houses. The predominant fungus taxa discovered in poultry houses were Eurotium spp. and thermophilic fungi. Cladosporium and Botrytis were mainly detected in greenhouses. The exposure level found in this study might put the farmers at risk from respiratory diseases.