The aim of the present study was to determine microbiological air quality in the Ciechocinek health resort and to identify the most common mesophilic bacteria present in the air. Sampling sites were located in the surroundings of inhalators (graduation towers and the “Grzyb” fountain), in recreation areas (promenade, parks), and urban areas. Samples were obtained by the impaction method in a Merck MAS-100 microbial airsampler. Enumeration of mesophilic bacteria was conducted according to the Polish Standard (PN86/Z- 04111/02). Bacterial strains were identified with appropriate API tests (bioMérieux). Due to the specific microclimate and low levels of microbiological air pollution, Ciechocinek can be considered an excellent upper respiratory tract spa. The lowest numbers of the investigated types of bacteria were found around the open inhalators. In the Ciechocinek area bacteria commonly occurring in air prevailed. Gram-positive bacilli (mainly Bacillus genus) were the most common among the isolated bacteria (53.8% of all strains), and Gram-positive cocci (Staphylococcus, Micrococcus) also were abundant (28%). The least abundant were Gram-negative rods (Pseudomonas, Serratia). Potentially pathogenic species (Pseudomonas aeruginosa, Enterococcus faecium, Aeromonas hydrofila) were found sporadically.