Because of the increasing importance of the newborn nursery in the occurrence of nosocomial epidemic infections, an investigation was conducted on the role of humidifying equipment in this connection. The results of this study indicate that an extremely high degree of gross contamination existed in the water of the humidifying devices in use in the newborn nursery. After the institution of the described procedures governing the care and cleansing of the humidification equipment, the degree of bacterial contamination was reduced to a low level.