The aim of the present study was to compare the clinical properties of fentanyl versus remifentanil in a target-controlled infusion (TCI) of propofol anesthesia regimen with bispectral index (BIS) monitoring. Forty consenting patients scheduled for elective septorhinoplasty were prospectively studied as one of two groups: fentanyl (group F) or remifentanil (group R). After loading boluses of fentanyl 3 mu g kg(-1) or remifentanil 1 mu g kg(-1) were administered, the continuous infusion of fentanyl or remifentanil was started at a rate of 0.03 or 0.15 mu g kg(-1) min(-1), respectively. Propofol infusion was then commenced with a 3 mu g ml(-1) effect site concentration (Ce) by means of a TCI device. The Ce propofol was adjusted to keep BIS at 50 +/- A 10. The general mean value of propofol Ce for group F and group R was 4.0 and 3.5 mu g ml(-1), respectively. As to the recovery profile, the eye opening time (mean, 6.7 vs. 4.6 min), extubation time (mean, 7.3 vs. 4.7 min), and orientation time (mean, 7.6 vs. 4.9 min) were found to be significantly longer in group F than in group R. We concluded that in propofol-based TCI anesthesia under BIS supervision for septorhinoplasty operations, remifentanil was better than fentanyl, especially with respect to emergence from total intravenous anesthesia (TIVA). Furthermore, the durations of anesthesia and operation were rather short, which indicates that fentanyl can be safely used.