Poultry production proved to be a significant source of bioaerosols. The exposure to high concentration of microorganisms in the air can cause primarily irritations, infections, allergies, and toxic effects. The aim of the present study was to investigate the seasonal biodiversity of airborne fungi in the poultry house, in the surrounding area, as well as to estimate health risk. Seasonal investigations were conducted in the spring, summer, autumn and winter 2010 in the poultry house located near Wrocław in Lower Silesia (Poland). The air samples were collected with the use of a Merck MAS-100 onto nutrient Sabouraud agar and were incubated for 5 days at 26 degrees C. Subsequently the colony-forming units (CFU) were determined. The identification of the isolated fungi was made in accordance with the standard procedures. In the summer and autumn when the weather conditions are most friendly for the spread and the development of numerous microorganisms, fungi were more abundant in the surrounding area than in early spring and winter, when both humidity and temperature were lower. The total of 26 species were analysed (10 in the poultry house and 17 in the surrounding areas). Among 12 fungal genera: Aspergillus, Penicilium, Alternaria, Exophiala, Mycelia sterilla, Fusarium, Cladosporium, Scopulariopsis, Chaetomium, Acremonium, Candida and Rhodotorula nearly everything occurred to be the potential respiratory allergens.