This study aimed to explore the short-term effects of percutaneous endoscopic transforaminal decompression (PETD) for the treatment of symptomatic double-level lumbar spinal stenosis (LSS) with ossification. Twenty-eight patients diagnosed with double-level lumbar spinal stenosis who underwent double-level PETD surgery between January 2021 and January 2023 at our institution. General information, such as age, sex, disease duration, hospitalization time, and operation time, was recorded. Magnetic resonance imaging (MRI) dural sac cross-sectional area (DSCA) was recorded to assess the degree of spinal canal decompression. The White-Panjabi scoring system (WP) was used to assess preoperative and postoperative lumbar spine stability. Pre- and postoperative visual analog scale (VAS) and Oswestry Disability Index (ODI) scores were recorded to assess symptom improvement, and surgical efficacy was evaluated using the modified Macnab evaluation criteria at the 1-year postoperative follow-up. The types and risks of complications were also recorded. The patient's 1-year postoperative follow-up MRI showed that both L3/4 and L4/5 DSCA were significantly enlarged compared with preoperative values (P < .001). There was no significant difference in the WP scores at 3 months postoperatively compared with those preoperatively (P > .05). The VAS scores for hip and lower extremity pain at 3 days, 3 months, and 1 year postoperatively were significantly lower than those preoperatively (P < .001), and the ODI scores at 3 months and 1 year postoperatively were significantly lower than those preoperatively (P < .001). There were no significant differences in hip pain, lower extremity pain VAS scores, or ODI scores between the postoperative follow-up time points (P > .05). There was 1 case of lower limb numbness and 1 case of neuroedematous pain in the postoperative period, and all patients had no complications, such as dural sac tear, infection, or recurrence. The 1-year postoperative follow-up was assessed as excellent in 17 cases, good in 9 cases, and possible in 2 cases using the modified Macnab criteria, with an excellent rate of 92.9%. The efficacy of double-level PETD for symptomatic double-level LSS is clear, the local stability of the lumbar spine is less affected, and the risk is low, which can reduce the chances of reoperation in patients. Thus, it is a recommended surgical procedure.