Abstract: Postoperative analgesia for the knee surgery in children can be challenging. Meanwhile acute pain management in pediatric patients is still often undertreated due to inadequate pain assessment or management. We reported the ultrasound-guided single-injection adductor canal block (ACB) with 0.2% ropivacaine and dexmedetomidine (0.5mg/kg) in addition in a series of 6 children. Patients’ age was range from 7 to 15 years old with right or left habitual patellar dislocation needing an open reduction and internal refixation. Pain assessments using Numeric Rating Scale scores on the operative limb were made preoperatively and at 12, 24, 36, and 48 h postoperatively at rest. Medication consumption was calculated as well. The possible complications, such as hemodynamic changes, nausea, vomiting, and dysesthesia, were also recorded at 12, 24, 36, and 48 h postoperatively at rest. The pain scores were low, and analgesic medication consumption was minimal. Meanwhile, no adverse events were recorded in any of the subject. Single-injection ACB might be an optimal analgesia strategy for patellar dislocation surgery in pediatric patients.