Objectives: To investigate the surgical safety and clinical efficacy of percutaneous endoscopic lumbar decompression (PELD) for lumbar spinal stenosis in elderly patients with medical complications. Methods: From January 2015 to December 2017, 27 elderly patients with lumbar spinal stenosis were performed PELD, all of who had medical complications and high risk of general anesthesia. There were 12 males and 15 females with an average age of 72.3±5.5 years (range 61-86 years). PELD for decompression of stenosis and treatment of intervertebral foramen was performed in all patients. The lumbar MRI were re-examined at 1 month and 12 months after operation to evaluate the decompression of nerve roots and stenosis. The leg pain VAS and ODI scores were recorded preoperatively and at 1 month, 3 months, 6 months and 12 months after operation, and statistical analysis was performed. The MacNab scores were evaluated after operation. Results: The average operation time was 81.3±27.2 min (range 60-120min). All patients were followed up for 19.6±10.1months (range 12-39 months). At 1 month and 12 months after operation, lumbar MRI showed great relaxed nerve root and satisfactory decompression of spinal stenosis.The leg pain VAS score decreased from 8.11±0.98 preoperatively to 1.79±0.67,1.36±0.55,1.10±0.51, and 0.84±0.44 at 1, 3, 6, 12 months after operation respectively. The ODI score also decreased from 62.8±11.3 preoperatively to 28.9±9.7,21.1±8.0,15.4±6.9, and 10.4±5.7 at 1, 3, 6, 12 months after operation respectively. Statistically significant differences existed in both VAS score(P<0.01) and ODI score(P<0.01) at each postoperative follow-up time point when compared with the preoperative scores. There were 16 excellent cases, 3 good cases and 4 fair cases according to the modified MacNab criteria, and the excellent and good rate was 87.5% after operation. There was no acute attack or aggravation of the co-existing medical conditions intrao- and post-operative in all patients. 1 case was found complicated with low extremity numbness, which recovered by conservative treatment for four weeks. No persistent neurological deficit, cerebrospinal fluid leakage, infect were founded in all patients. Conclusions: For elderly patients with medical complications and high risk of general anesthesia, PELD can be accomplished in a shorter operation time and less invasive, which could be performed under simple local anesthesia and has less impact on the general condition of patients. In addition, this technique is safe and satisfactory for treating lumbar spinal stenosis.