ObjectiveTo compare the effectiveness between unilateral laminotomy and bilateral decompression (ULBD) with unilateral biportal endoscopy (UBE) and uniportal interlaminar endoscopy (UIE) in the treatment of lumbar spinal stenosis. Methods A clinical data of 52 patients with lumbar spinal stenosis, who met the selection criteria and treated with ULBD between March 2021 and November 2022, was retrospectively analyzed. The patients were allocated into UBE group (23 cases) and UIE group (29 cases) according to the surgical methods. There was no significant difference (P>0.05) in age, gender, body mass index, surgical segment, type of lumbar stenosis, and preoperative visual analogue scale (VAS) score of low back pain, VAS score of leg pain, Oswestry disability index (ODI), disc height, and dural sac area between the two groups. Perioperative indexes (incision length, operation time, hospital stay, and surgical complications), clinical indicators (VAS score of low back pain, VAS score of leg pain, and ODI before operation and at 3 days, 1 month, 6 months, and 12 months after operation), and imaging indicators (disc height and dural sac area before operation and at 1, 12 months after operation, and dural sac expansion area) were recorded and compared between the two group. Results All operations in both groups were successfully completed. Compared with the UIE group, the UBE group had shorter operation time and longer incision length, with significant differences (P<0.05). But there was no significant difference in hospital stay and incidence of complications between the two groups (P>0.05). All patients were followed up 12-20 months (mean, 14 months). The VAS scores of low back pain and leg pain and ODI after operation significantly improved when compared with preoperative values (P<0.05), and there was no significant difference in the above indicators between different time points after operation (P>0.05). There was no significant difference between the two groups at different time points (P>0.05). Imaging examination showed that there was no significant difference in disc height between the two groups at different time points after operation (P>0.05). However, the dural sac area and dural sac expansion area were significantly larger in the UBE group than in the UIE group (P<0.05). Conclusion ULBD with UBE and UIE can achieve satisfactory effectiveness in the treatment of lumbar spinal stenosis. But the former has more thorough decompression and better dural sac expansion than the latter.