Glutaraldehyde (GTA) solutions can be used for low-temperature endoscopes disinfection. The research aim was to evaluate the aldehyde air-contamination in Campania hospitals operating theatres produced by the use of two-percent glutaraldehyde alkaline solution. Air samples were analysed by HPLC-UV (Hight Performance Liquid Chromatography with UV detection). The final results show that some operating theatres have a significant GTA air-contamination with a substance concentration upper limit value (0,05 ppm), due to not-well ventilated workplaces and the presence of not-automatic washing units.