We compared loss of pulse oximetry signal (dropout rates) for both finger and forehead sensors in postanesthesia patients. Pulse oximetry is a widely practiced method for measuring oxygen saturation. Several studies in various patient populations have demonstrated that low flow states, patient movement, and hypothermia may result in poor signal quality with the use of finger oximetry sensors. These clinical conditions are common in patients as they emerge from anesthesia. New forehead sensors may reduce signal dropout. A method-comparison design was used to compare finger and forehead oximetry signal dropout rates. Of 48 subjects studied, only three had a signal dropout. Overall, there were seven episodes of signal dropout; six of seven occurred with the finger sensor. Signal dropout occurred rarely in PACU subjects. Use of finger sensors for routine postanesthesia monitoring should be adequate in the majority of patients.