摘要:Graphical abstractDisplay OmittedAbstractThis study was aimed to investigate the types and number of bacterial and fungal bioaerosols in indoor air of hospitals according to the type of wards and operating theaters. Bacterial and fungal samples were collected using the passive sampling method of 1/1/1 scheme during a six months' period in the Khatam-Al-Anbia hospital, Tehran, Iran. A simple linear regression was used to determine the relationship between bioaerosol concentrations and the number of active beds. Bacterial bioaerosol concentrations were mainly higher than fungi in all sampling sites. A significant association was found between airborne fungal concentrations and the numbers of beds (R2 = 0.76, p < 0.05), but not observed for bacteria (R2 = 0.02, p < 0.05). Our findings provided an exposure database of airborne bacterial and fungal bioaerosol in hospital wards and operating theaters in Tehran.•Due to the importance of the exposure risk to bioaerosols for patients and medical personnel, we focused on identification of the density and diversity of bacterial and fungal bioaerosols in different wards and operating theaters.•Our results showed that the numbers of the beds have a significant effect on airborne fungal concentrations.•The results of this study can be used to set indoor air quality standards for hospital wards and operating theatres.