Central sensitization is abnormal and intense enhancement of pain mechanism by the central nervous system. Patients with central sensitization may be at higher risk of poor outcomes after spinal fusion. The Central Sensitivity Inventory (CSI) was developed to identify and quantify key symptoms related to central sensitization. In 664 patients who underwent thoracic and/or lumbar fusion, we evaluated retrospectively pretreatment CSI as a predictor of postoperative quality of life measures, length of stay, and discharge status. Preoperative Pain Disability Questionnaire scores, Patient Health Questionnaire-9 scores, and EuroQol-5 Dimensions index scores were significantly worse in patients with preoperative CSI ≥40 compared with patients with preoperative CSI <40 (P < 0.0001 for all). After adjusting for demographic variables, operation duration, and preoperative health status, preoperative CSI was significantly associated with higher postoperative Pain Disability Questionnaire total score (unadjusted P<0.001, adjusted P= 0.009), higher postoperative Patient Health Questionnaire-9 score (unadjusted P < 0.001, adjusted P= 0.001), and lower postoperative EuroQol-5 Dimensions index (unadjusted P < 0.001, adjusted P= 0.001). For each 10-unit increase in CSI, average length of stay increased by 6.4% (95% confidence interval 0.4%-12.6%, P= 0.035). The odds of being discharged home after adjusting for confounders was not statistically related to preoperative CSI (P= 0.0709). Preoperative CSI was associated with worse quality of life outcomes and increased length of stay after spinal fusions. CSI may be an additional measure in evaluating patients preoperatively to better predict successful spinal fusion outcomes.