Studies of indoor bioaerosols conducted in Central and Eastern European countries, as a result of the scarcity of funding, mostly do not attain the level presented by similar studies in Northern America and Western Europe. For socio-economic reasons, most of the intense studies on indoor bioaerosols in Central and Eastern European countries were carried out in industrial facilities and have contributed significantly to occupational health science. In contrast, until recently, insufficient of studies have been conducted on bioaerosols of residential and communal premises (dwellings, offices, schools, etc.) and no network for monitoring the microbiological quality of air in such premises exists. In Poland, in the mid-1990s complex bioaerosol investigations were carried out by the Bioaerosol Group at the Institute of Occupational Medicine and Environmental Health in Sosnowiec. The concentrations of airborne bacteria and fungi in dwellings without mold problems were between 88-4297 cfu/m(3) and 0-1997 cfu/m(3), while in moldy homes they were 178-4751 cfu/m(3) and 49-16,968 cfu/m(3), respectively. As many as 167 microbial species were isolated from the air of examined dwellings. Most frequently occurred Gram-positive cocci (Micrococcus/ Kocuria spp., Staphylococcus spp.), endospore-forming bacilli (Bacillus spp.), Gram-negative bacteria (Pseudomonadaceae, Aeromonas spp.), filamentous fungi (Penicillium spp., Aspergillus spp.), and yeasts. Notable studies of indoor bioaerosols have also been performed in the other Central and Eastern European countries: Lithuania, Latvia, Estonia, Russian Federation, Ukraine, Czech Republic, Slovakia, Bulgaria and Hungary, are reviewed in this article. The lack of reference limit values for bioaerosols seriously hinders interpretation of results obtained in various countries. The following residential limit values (RLV) for dwellings and communal premises are proposed for the concentration of airborne bacteria, fungi and bacterial endotoxin: 5 x 10(3) cfu/m(3), 5 x 10(3) cfu/m(3) and 5 ng/m(3) (50 EU), respectively. The proposed values of occupational exposure limit (OEL) for industrial settings contaminated by organic dust are 100 x (3) cfu/m(3), 50 x (3) cfu/m(3) and 200 ng/m(3) (2000 EU), respectively. It is also proposed that the presence in indoor air of microorganisms from risk groups 3 and 4 of European Community Directive 2000/54/EC (e.g., Mycobacterium tuberculosis, Bacillus anthracis, Coxiella burnetii), independently of the concentration, should always be inadmissible and result in preventive actions.