Background: In spinal deformity surgery, posterior column osteotomies (PCOs) are used to increase spinal flexibility and permit greater deformity correction, while avoiding the morbidity of anterior column surgery. Complications related to use of PCOs have been well characterized in adults; however, there is a paucity of information in the pediatric population. Methods: A single-surgeon retrospective analysis was completed of 484 PCOs in 142 patients (average age: 14.5 years) undergoing spinal deformity surgery. All surgeries were completed by a standard posterior approach using a midline incision and dual-rod, pedicle screw constructs. PCO-related complications were recorded (intraoperative monitoring alerts, postoperative neurologic deficit, dural tear/violations, cerebrospinal fluid [CSF] leak, pseudarthrosis, etc.) and analyzed by diagnosis (idiopathic, congenital, neuromuscular, syndromic). Results: The diagnoses for the 142 patients were idiopathic (103 patients), neuromuscular (23 patients), syndromic (14 patients), and congenital (2 patients). In a subset of 87 patients with 2-year radiographic follow-up, the preoperative major coronal Cobb measurement was 75.5° ± 17.6° which corrected to 34.9° ± 17.5° postoperatively and 37.8° ± 17.9° at last follow-up (p <.0001, p <.0001). Complications evaluated were postoperative neurologic deficit (0% of patients, 0/142), dural tears/violations at site of PCO (0.4% of PCOs, 2/484), CSF leak (0% of patients, 0/142), and pseudoarthrosis at site of PCO (0% of PCOs, 0/290). Conclusion: The overall frequency of complications related to PCOs was 0.4% (0.4% dural tears/violations) with 0% postoperative neurologic deficit, CSF leak, or pseudarthrosis. Based on these data, PCOs appear to be a safe technique in pediatric spine deformity surgery, with a low rate of technique-related complications. Study Design: Retrospective case series. Objectives: To report the frequency of posterior column osteotomy complications (neurologic deficit, dural tear, cerebrospinal fluid leak, and pseudarthrosis) in pediatric patients undergoing spinal deformity surgery. Level of Evidence: Level IV.