Abstract: Objective　To evaluate the efficacy of dexmedetomidine sedation combined with ropivacaine caudal block in perineal anoplasty in neonates. Methods　Eighty neonates scheduled for elective perineal anoplasty were divided into 2 groups (n=40 each) using a random number table: dexmedetomidine group (D group) and control group (C group). In group D, dexmedetomidine was given at a bolus dose of 1 μg/kg over 10 min. When the Ramsay score reached 3-4, caudal anesthesia was performed using a single dose of 0.2% ropivacaine 1 mL/kg in the left lateral position. Sedation was maintained with dexmedetomidine infusion at the rate of 0.2-1 μg/(kg·h) to maintain a Ramsay score of 3-4 and discontinued at the end of surgery. Neonates in group C were induced by intravenous anesthesia, after tracheal intubation, caudal anesthesia was performed using a single dose of 0.2% ropivacaine 1 mL/kg in the left lateral position. Heart rate, percutaneous oxygen saturation and mean arterial pressure were recorded at the following times: into the operation room (T0), at the beginning of the operation (T1), fixation of the perianal (T2), at the end of the operation (T3) and out of the operation room (T4). Data of anesthesia time, operation time and recovery time, the incidence of hypoxemia in the operating room, respiratory depression/suspension, cough, laryngospasm, bronchospasm and sacral block related complications during the operation, recovery and stay in the anesthetic resuscitation room (PACU) were recorded. Results　Compared with group C, heart rate decreased and mean arterial pressure increased at T1, T2, T3 and T4, and oxygen saturation decreased at T2 and T3 in group D (P＜0.05). The recovery time was significantly shorter in group D than that of group C (P＜0.05). Compared with group C, the incidence of respiratory depression/suspension, cough, laryngospasm, bronchospasm and stay in PACU were significantly lower in group D than that in group C (P＜0.05). Conclusion　Dexmedetomidine sedation combined with ropivacaine caudal block is safe and effective in neonates for perineal anoplasty.