The aim of this study was to assess microbiological indoor air quality of selected bakeries located in the region of Podlasie. The microbiological studies were conducted in autumn in 2014 in three selected bakeries. Microbiological air counts were measured by impaction using an air sampler MAS-100 NT. The microbiological air studies, comprised the determination of the total number of psychrophilic and mesophilic bacteria, namely indicator bacteria such as: bacteria of the species Pseudomonas fluorescens, mannitol-positive and mannitol-negative Staphylococc, the total number of bacteria from the Enterobacteriaceae family and fungi found in atmospheric air. The results of the study of indoor air polluted with the analyzed groups of microorganisms differed depending on the type of test air and the location of the manufacturing plant. In the plants, the concentration of mesophilic bacteria and mannitol–positive and mannitol-negative Staphylococcus exceeded the limit values of unpolluted air, according to the Polish Standard recommendations.