BACKGROUND: The aim of this study was to compare dexmedetomidine (DEX), which is a selective, short-acting, central alpha2-adrenergic agonist, with fentanyl in terms of the hemodynamic stability, achieving hypnosis and sedation, and the postoperative pain control at the PACU (postanesthetic care unit). METHODS: In this double-blind study, 50 consecutive total laparoscopic hysterectomy patients scheduled for elective surgery were randomly assigned to receive either dexmedetomidine 1 microg/kg over 10 min followed by a 0.5 microg/kg/hr infusion (the DK group) or fentanyl 0.8-1.2 microg/kg over 1 min followed by a 0.2-0.6 microg/kg/hr infusion (the FK group) from the time of ending the operation after total hysterectomy to the time in the PACU. We evaluated the pain VAS scores, the modified OAA/S scores, the BIS, the vital signs, the respiratory variables (SpO2, RR and EtCO2) and the perioperative side effects to compare the efficacy of dexmedetomidine and fentanyl. RESULTS: Compared with the fentanyl-ketorolac (FK) group, the modified OAA/S scores were significantly lower in the dexmedetomine-ketorolac (DK) group at 0, 5 and 10 min after arrival at the PACU (P < 0.05), whereas the pain VAS and BIS were not significantly different between the two groups. The blood pressure and heart rate in the DK group was significantly lower than that of the FK group at the PACU (P < 0.05). CONCLUSIONS: The DK group, at the doses used in this study, has a significant advantage over the FK group in terms of the postoperative hemodynamic stability at the PACU. There was no significant difference between the two groups for the postoperative pain control.