Bioaerosols are airborne particles, composed by living beings or large molecules that have been released by another living being and that can contribute to the transmission of infections. The purpose of this study is to evaluate the risk for the transmission of nosocomial respiratory infections mediated by bioaerosols, by monitoring the microbiological quality of the air in the Emergency area with an air sampler. From what is gathered a quantification and characterization of microorganisms in the hospitals environment is performed. The preliminary results of the research information establishes the existence of a microbiological contamination tied to favorable environmental conditions and characteristics of different substrates, results in the growth and development of organisms. It also indicates that air conditioning systems can represent an indoor air quality risk, creating a scenario with not acceptable levels of microorganisms such as Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aereus, Klebsiella pneumoniae and Aspergillus, which are opportunistic microorganisms that contribute to the increase of the morbidity and mortality in hospitals patients. The scientific review conducted in Colombia, leads to the conclusion that currently prevention, control and surveillance policies of epidemiologic nosocomial infections are not implemented, even if they are defined in different regulations such as resolution 073 2008. This implies that these institutions need to take corrective action involving a high cost that will translate into the reduction of health effects on workers and patients, which currently constitutes a public health problem.