Continuous pulse oximetry (CPOX) has the potential to increase vigilance and decrease pulmonary complications and thus decrease intensive care unit (ICU) admissions. In a randomized nonblinded study of 1219 subjects we compared the effects of CPOX and standard monitoring on the rate of transfer to an ICU from a 33-bed postcardiothoracic surgery care floor. There was no difference in the rate of ICU readmission between the CPOX and standard monitor groups. Despite older age and comorbidity, estimated cost to time of censoring (enrollment to completion of the study) was less in the monitored patients who required ICU transfer than in the unmonitored patients who required ICU transfer (mean estimated cost difference of 28,195 dollars; P = 0.04). Use of CPOX altered the reasons that patients were transferred to an ICU but did not affect the rate of transfer. The duration, and thus estimated cost, of ICU stay was significantly less in the CPOX-monitored group. The potential for CPOX to allow for early intervention, or perhaps prevention of pulmonary complications, needs to be explored. Routine CPOX monitoring did not reduce transfer to ICU, mortality, or overall estimated cost of hospitalization, and it is unclear if there is any real benefit from the application of this technology in patients on a general care floor who are recovering from cardiothoracic surgery.