OBJECTIVE: The purpose of this study was to assess the feasibility of minimally invasive transforaminal lumbar interbody fusion (TLIF) and bilateral decompression via a unilateral approach that was performed with a novel working retractor with an endoscopic system for degenerative lumbar spondylolisthesis associated with spinal stenosis, to minimize surgical trauma without compromising the quality of the treatment outcome. METHODS: In this case series, the procedure was performed in 17 patients. Patient outcomes were scored according to operating time, intraoperative blood loss, visual analog scale, Oswestry Disability Index, Japanese Orthopaedic Association scores, and postoperative imaging studies. RESULTS: The follow-up period was 1 year. All patients showed clinical improvement, based on the visual analog scale, Oswestry Disability Index, and Japanese Orthopaedic Association score (P < 0.01). At 12 months postoperatively, all patients achieved solid bone graft fusion. CONCLUSION: The use of navigation-assisted endoscopic TLIF with bilateral decompression via a unilateral approach appears safe and feasible. The endoscopic surgical procedure may be an alternative surgical option for degenerative lumbar disease.