Study design: Multivariate analysis of retrospective registry data. Objective: To report the perioperative complication in a large cohort of surgery for elderly degenerative lumbar scoliosis (DLS) patients and to analyze the risk factors. Summary of background data: The perioperative complication rate and risk factors for patients with DLS remain unclear, especially in elderly population. Methods: Between November 2015 and June 2018, 98 patients aged 70 or older with DLS received decompression and intervertebral fusion by one spine surgeon at Beijing Xuanwu Hospital. The medical history and comorbidities of all patients were recorded. Results: The perioperative complication rate was 34.7% in all patients, 11.2% of all patients had major complications, and 31.6% had minor complications. The major complication most commonly seen was wound infection, and the most common minor complication was hypoproteinemia. Elderly patients (>75) had longer hospital stays (17.5 ± 7.9) when compared to younger patients. Two risk factors of perioperative complications were chosen after binary logistic regression analysis: Lower BMI and longer instrumented segments. The only risk factor for major complications was longer instrumented level (≥3), and the only risk factor for minor complications was lower BMI. Conclusion: Our findings indicate that in elderly patients with DLS, lower BMI is a risk factor for minor perioperative complication. Obesity is not a major problem in this population, on the contrary, BMI is a protective factor for perioperative complications. The risk factors for major perioperative complications in elderly patients with DLS are longer instrumented segments but not related to the number of decompression and intervertebral fusion levels. Preoperative comorbidities and advanced age were not associated to a higher perioperative complication rate in elderly patients. The perioperative complication rate in patients with DLS over 70 years of age is found to be acceptable with appropriate perioperative management. © 2019 Ding et al.