Postoperative emergence agitation/delirium (POED) is a common complication in pediatric surgery patients, which increases the risk of developing postoperative airway obstruction and respiratory depression. This study aims to investigate the safety and efficacy of intraoperative infusion of dexmedetomidine (DEX) and its effects on POED in pediatric patients undergoing tonsillectomy with or without adenoidectomy.Sixty patients scheduled for tonsillectomy with or without adenoidectomy, aged 2 to 8 years, were randomly allocated into 2 groups (n = 30). Pediatric patients in the group DEX received intravenous (IV) DEX 1 μg/kg over 10 minutes, followed by 0.5 μg/kg/h continuous infusion, and the same volume of 0.9% saline was administrated in the group control. Anesthesia was maintained with target-controlled infusion (TCI) of propofol and remifentanyl. Intraoperative heart rate (HR), noninvasive blood pressure (NIBP), blood oxygen saturation (SPO2), recovery time, and extubation time were recorded. Pain level was evaluated using the objective pain score (OPS), pediatric anesthesia emergence delirium (PAED) scale and Cole 5-point scale (CPS) was used to evaluate POED when patients at 0, 5, 15 minutes, and then at intervals of 15 minutes for 60 minutes after parents arrival at postanesthesia care unit (PACU).The results showed that intraoperative HR was significantly lower in group DEX (P <0.05), mean diastolic and systolic NIBP was not statistically different between groups. Time to wake and time to extubation were lengthened in group DEX as compared with group control (P <0.05). OPS and CPS were lower in group DEX at 15, 30, and 45 minutes time points (P <0.05); however, there were no significantly differences in the PAED score at different time points in the PACU.The present data suggested that intraoperative infusion of dexmedetomidine combined with intravenous anesthetics can provide satisfactory intraoperative conditions for pediatric patients undergoing tonsillectomy with or without adenoidectomy, without adverse hemodynamic effects, though the lower incidence of POED was not observed.