Contaminated pressure monitoring devices recently have been implicated as a source of epidemic organisms in three outbreaks of nosocomial bacteremia, one outbreak of candidemia, and one outbreak of hepatitis. Measures necessary to prevent monitoring-related infections have not always been appreciated or taken. As a minimum, pressure monitoring devices should be sterilized between use with different patients; strict aseptic technique should be employed when setting up and using monitoring systems; and each patient's monitoring tubing, fluid, and monitoring devices should be changed at regular intervals.