Background: In recent years, the number of people suffering from diseases caused by fungi has been increasing. However, knowledge of the biodiversity of fungal pathogens in the work environment is still insufficient. The aim of this work was to evaluate the exposure to fungi being disseminated in the air of workplaces contaminated with organic dust of plant and animal origin. Material and Methods: Bioaerosol samples were collected at 3 occupational settings (poultry farm, biomass burning power plant and wastewater treatment plant) using button samplers. Quantitative and qualitative analysis of fungal aerosol was conducted by employing macro- and microscopic methods. Selected strains were then studied by polymerase chain reaction (PCR) using środointernal transcribed spacers (ITS): ITS1–ITS2, ITS3–ITS4 and ITS1–ITS4 primer pairs. Results: Average concentrations of fungal aerosol at workplaces ranged 1.2×102–2.1×106 cfu/m³. The highest fungal concentrations were recorded in the poultry farm, while the lowest were noted at the wastewater treatment plant. Aspergillus fumigatus was a predominant component of the mycobiota in the power plant and wastewater treatment plant. Almost 100% identification agreement of this pathogen between the traditional and molecular method was noted. Conclusions: The fungal concentrations in poultry farms exceeded the Polish proposal for the threshold limit value (5×104 cfu/m³). The results of the study demonstrate a high compatibility of A. fumigatus’ identification using the traditional and molecular methods. Taking into account the fact, that a long term exposure to A. fumigatus conidia at workplaces may result in numerous health complaints, the use of proper protective equipment by workers must be a standard procedure. Med Pr 2018;69(3):269–280