BACKGROUND CONTEXT Surgical site infection (SSI) remains a serious complication of adult spinal deformity (ASD) surgery. Although fusion/instrumentation failure in the setting of SSI has been reported, few studies have investigated the relationship between these entities. PURPOSE To examine the relationship between early SSI and fusion/instrumentation failure after instrumented fusion in adult patients with thoracolumbar scoliosis. STUDY DESIGN/SETTING A retrospective review of a prospectively maintained case series for patients undergoing spine surgery between January 1, 2006, and October 3, 2017 at a single institution by a single surgeon team. Inclusion criteria included age ≥18 years and surgery performed for correction of thoracolumbar scoliosis. Data collected included various demographic, clinical, and operative variables. PATIENT SAMPLE There were 532 patients >18 years old who underwent thoracolumbar instrumented fusion surgery for the correction of scoliosis. OUTCOME MEASURES The following outcome measures were used: rate of surgical site infection, hardware failure, need for revision surgery, time to revision surgery. METHODS A retrospective review of a prospectively maintained case series for patients undergoing spine surgery between January 1, 2006, and October 3, 2017 at a single institution by a single surgeon team. Inclusion criteria included age ≥18 years and surgery performed for correction of thoracolumbar scoliosis. Data collected included various demographic, clinical, and operative variables. RESULTS A total of 532 patients met inclusion criteria, with 20 (4%) experiencing SSI. Diabetes mellitus was the only demographic risk factor for increased SSI (P = 0.026). Number of fused levels, blood volume loss, and operative time were similar between groups. Fusion/instrumentation failure occurred in 68 (13%) patients, 10 of whom (15%) had SSI, whereas of the 464 patients with no fusion/instrumentation failure, only 10 (2%) had SSI (P CONCLUSIONS Early SSI significantly increases the risk of fusion/instrumentation failure in patients with thoracolumbar scoliotic deformity, and it significantly shortens the time to failure. Patients with early SSI have a significantly higher likelihood of requiring revision surgery and after a significantly shorter time interval. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.