In order to find out the mycoflora prevailing in chicken pens, and to appreciate the health hazards for employees (incl. veterinarians) and animals, twenty litter samples and 6 sedimented dust trials were analysed mycologically. The following results were found: Bedding and dust samples all contained between 3.57 and 1.30 x 10(7) c.f.u./g DW. The commonest fungus is A. fumigatus with 3.41 x 10(4) - 1.30 x 10(7) c.f.u./g DW in bedding and 2.70 x 10(5) - 3.30 x 10(6) c.f.u./g DW in sedimented dust. In addition, the following fungal spp. were detected (in c.f.u./g DW):;Scopulariopsis brevicaulis (3.57 x 10(3) - 6.50 x 10(7)), Pseudallescheria boydii (2.70 x 10(6)), A. flavus group (up to 8.41 x 10(5)), A. clavatus (6.00 x 10(5)), Candida albicans (4,88 x 10(5)), Alternaria spp. (4.49 x 10(5)) Penicillium spp. (up to 1.06 x 10(5)), A. terreus (8.47 x 10(4)), A. versicolor group (up to 8.44 x 10(4)), A. niger (5.93 x 10(4)), Aureobasidium sp. (3.96 x 10(3)), Mucor circinelloides (3.42 x 10(3)), Phialophora sp. (1.30 x 10(3)), C. pseudotropicalis (4.04 x 10(2)), A. nidulans (3.90 x 10(2)), Acremonium sp. (3.55 x 10(2)), M. racemosus (1.19 x 10(2)). Negligible was the detected level of Chrysosporium pannorum (84.10), Rhizomucor pusillus (81.00), Beauveria alba (59.60), C. tropicalis (40.40), Trichoderma sp. (4.70), A. flavipes (4.38). Dermatophytes were not found. The fungal spectrum was broader in the dust than in litter samples.