Objective To evaluate the effect of dexmedetomidine on postoperative outcomes in ped?iatric patients undergoing open reduction and internal fixation following upper limb fracture performed under sevoflurane anesthesia combined with brachial plexus block. Methods Sixty American Society of Anesthe?siologists physical status Ⅰ pediatric patients of both sexes, aged 6-12 yr, with body mass index <24 kg∕m2, scheduled for elective open reduction and internal fixation following upper limb fracture, were ran?domly divided into ropivacaine group(group R)and dexmedetomidine mixed with ropivacaine group (group DR), with 30 cases in each group. Interscalene brachial plexus block was performed under ultra?sound guidance after sevoflurane anesthesia, 0.25% ropivacaine plus 1 μg∕kg dexmedetomidine(0.3 ml∕kg)was given in group DR, and 0.25% ropivacaine 0.3 ml∕kg was given in group R. The emergence time was recorded, and the development of agitation was observed immediately after emergence from anes?thesia. Sensory block duration, motor block duration, consumption of sedatives and analgesics during post?anesthesia care unit(PACU), consumption of rescue analgesics within 24 h after operation, length of stay in PACU and adverse reactions in the perioperative period were observed and recorded. Results Compared with group R, the incidence of agitation immediately after emergence from anesthesia was significantly de?creased, sensory block duration was prolonged, the consumption of sedatives and analgesics during PACU and rescue analgesics within 24 h after operation was reduced, and the emergence time and length of stay in PACU were prolonged in group DR(P<0.05). There was no significant difference in the incidence of bradycardia between the two groups(P>0.05). No adverse reactions were found in the perioperative period in the two groups. Conclusion Dexmedetomidine can promote postoperative outcomes in pediatric patients undergoing open reduction and internal fixation following upper limb fracture performed under sevoflurane anesthesia combined with brachial plexus block.