Objective To compare the clinical efficacy of the transforaminal endoscopic lumbar discectomy （TELD） approach with that of the interlaminar endoscopic lumbar discectomy （IELD） approach， both performed using a single-channel spinal endoscope， in the treatment of L4-L5 degenerative lumbar lateral recess stenosis （DLLRS）. Methods A retrospective analysis was conducted on 78 patients with L4-L5 DLLRS who underwent single-channel endoscopic spinal surgery at our institution between March 2020 and March 2024. Patients were classified into the TELD group （lateral transforaminal approach， n = 34） and the IELD group （interlaminar approach， n = 44）. Propensity score matching （PSM） was performed in a 1∶1 ratio using age， sex， body mass index （BMI）， and duration of symptoms as covariates， yielding 25 matched pairs for final comparative analysis. Perioperative outcomes were systematically compared between groups. Visual analog scale （VAS） scores for low back pain and leg pain， as well as the Oswestry Disability Index （ODI）， were evaluated preoperatively and at 3 days， 3 months， 6 months， and 1 year postoperatively. Lumbar computed tomography （CT） scans obtained 3 days after surgery were used to measure the lateral recess angle （LRA） and assess the extent of decompression. Spinal stability was evaluated using dynamic lumbar radiographs at 3 months postoperatively. Clinical outcomes were assessed 1 year after surgery based on the modified MacNab criteria. Results Both groups showed significant reductions in VAS scores for low back and leg pain， as well as in ODI scores， at all postoperative time points compared to baseline values （P < 0.05）. However， no statistically significant differences were observed between the two groups （P > 0.05）. Lumbar CT scans performed on postoperative day 3 demonstrated a significant increase in LRA in both groups relative to preoperative measurements （P < 0.05）. Although the magnitude of increase was greater in the IELD group， the intergroup difference did not reach statistical significance （P > 0.05）. At 3 months postoperatively， dynamic lumbar radiographs revealed no deterioration in spinal stability in either group compared to preoperative conditions， with no significant difference between groups （P > 0.05）. According to the modified MacNab criteria at 1 year postoperatively， the excellent and good outcome rate was 88.0% in the TELD group and 92.0% in the IELD group， with no statistically significant difference between the groups （P > 0.05）. Conclusions Both the TELD and IELD techniques are safe and effective for managing L4-L5 DLLRS， yielding comparable clinical outcomes. The selection of surgical approach should be guided by the anatomical location of ventral disc protrusions， as well as the degree of facet joint hypertrophy and neural compression.