After infection by Gram negative bacteria, neonatal patients or patients in intensive care unit usually sufferfrom endotoxin shock, leading to death finally in spite of eradication of bacteria by potent antibiotics. Thepurpose of this study that is the pilot study to prevent endotoxin shock and nosocomial infection, is to offerbasic data on species and concentrations of airborne microbes in hospitals. Therefore, this study collectedand analyzed articles and documents on airborne microbes in hospitals in Korea that were published inrelevant journals from 1980 to 2004. Studies on the concentration of airborne microbes in hospitals as apart of study on the nosocomial infection have been performed from the latter half of 1970s. Pooled averageconcentrations of total suspended bacteria in hospitals by RCS air sampler and Cascade air sampler were194.85 CFU/㎥ and 367.72 CFU/㎥, respectively. They were lower than the guideline concentration(800 CFU/㎥) of the Korean Ministry of Environment. Pooled average concentrations of total suspended fungi inhospitals by RCS air sampler and Cascade air sampler were 20.66 CFU/㎥ and 193.34 CFU/㎥, respectively.They were lower than the guideline concentration(150 CFU/㎥) of the World Health Organization(WHO).Pooled average concentrations of total suspended bacteria in operating room and intensive care unit(ICU)were 324.75 CFU/㎥ and 182.43 CFU/㎥, respectively. They again were lower than the guideline concentrationof the Korean Ministry of Environment. Staphylococcus spp., Micrococcus spp., and Lactobacillus spp. forGram-positive bacteria, and Pseudomonas spp., Klebsiella spp., and Escherichia spp., for Gram-negativebacteria were shown in hospitals. Also, Aspergillus spp., Penicillium spp., Mucor spp., Epidemophyton spp.,Trichophyton spp., and Cladosporium spp. for fungi were found in hospitals. Staphylococcus spp. was shownfrequently in operating rooms, intensive care units and wards. Penicillium spp. and Aspergillus spp. wereshown commonly in them.