Objective This study aimed to evaluate the short-to-medium term clinical efficacy of Minimally Invasive Modified Extraforaminal Lumbar Interbody Fusion (MIS-mELIF) in treating lumbar degenerative diseases, and explore its effectiveness, safety, and feasibility. Methods Clinical data from 31 patients with single-segment lumbar degenerative disease who underwent MIS-mELIF surgery at our hospital from January 2022 to March 2024, with at least 12 months of postoperative follow-up, were analyzed. Evaluation parameters included: (1) perioperative indicators: operative time, intraoperative C-arm fluoroscopy frequency, intraoperative blood loss, postoperative drainage volume, and complications; (2) clinical outcomes: Visual Analog Scale (VAS) scores, Oswestry Disability Index (ODI), and Japanese Orthopaedic Association (JOA) scores assessed preoperatively and at immediate postoperative, 1-, 3-, 6-, and 12-month follow-ups; (3) radiographic parameters: segmental lordosis angle (SLA) and disc height (DH) measured preoperatively and at immediate postoperative, 1-, 3-, and 12-month follow-ups. Final follow-up assessments included Brantigan and Steffee fusion grading criteria for interbody fusion status, cage subsidence/migration, and instrumentation loosening/fracture. Results All patients completed ≥12-month follow-up (12-37 months). Mean operative time was 124.92±8.16 minutes with 18.52±2.07 C-arm exposures, 65.37±14.25 ml intraoperative blood loss, 30.14±8.89 ml postoperative drainage, 3.32±2.04 g/L postoperative hemoglobin decline, and 5.36±2.31 days hospital stay duration. Significant improvements in VAS, ODI, and JOA scores were observed at all postoperative timepoints compared to baseline. SLA and DH showed significant postoperative restoration and maintenance. Only one case exhibited postoperative dorsal root ganglion irritation, with no neurological injuries, dural tears, or cerebrospinal fluid leaks. Brantigan-Steffee grading revealed Grade D-E fusion in all cases at final follow-up, with no significant cage migration/subsidence or instrumentation failure.Conclusion MIS-mELIF demonstrates favorable clinical outcomes for lumbar degenerative diseases, characterized by enhanced minimally invasive features, proving to be a safe, effective, cost-efficient, and technically accessible surgical approach