A pulse oximetry (SpO2) knowledge survey was conducted with 551 experienced critical care nurses at the 2002 American Association of Critical Care Nurses National Teaching Institute in Atlanta, GA. Results of this survey indicated an increased level of knowledge about SpO2 technology and monitoring compared to that reported in previous studies. These findings are important, because critical care nurses are responsible for providing care to the most critically ill patients. Critically ill patients are most likely to have decreases in their pulse oximetry values that require immediate interventions. In addition, critically ill patients are also the most likely group of patients to exhibit the clinical conditions that adversely affect pulse oximetry signal quality, including low perfusion and patient motion artifact. The ability of critical care nurses to correctly assess pulse oximetry values within the context of the technology limitations and the critical care environment is important in providing optimal care to critically ill patients.