Background Spinal fusion, the basis for Lumbar arthrodesis, relies on accurate identification of the etiology, pathology, and anatomic diagnosis. This study investigates the functional outcome of transforaminal lumbar interbody fusion (TLIF) in managing Lumbar Spondylolisthesis. Methodology This prospective observational study was conducted over a year at a hospital. Thirty patients with Lumbar Spondylolisthesis, including 14 men and 16 women, were selected. The average age was 50.9 ± 5.6 years, ranging from 40 to 63 years. Diagnostic evaluations included blood tests (Serum Vit-D, Calcium, alkaline phosphatase), radiological investigations (Chest X-Ray, Lumbosacral spine X-Ray, MRI, pelvis X-Ray, Myelography, Bone-scan, and CT scan). Clinical follow-ups were conducted immediately post-operation, at 2 weeks, 6 weeks, 3 months, and 6 months. Results Among the 30 cases, there were 13 L5-S1, 16 L4-L5, and 1 L2-L3 Spondylolisthesis cases. Radiological fusion was observed in 16.66% of patients. Functional outcomes showed significant improvements in VAS and ODI scores, correlating with marked improvements in axial and radicular symptoms, leading to increased patient satisfaction. Conclusion TLIF is a versatile approach effective across all lumbar levels. Success hinges on proper patient selection and accurate diagnosis correlating with symptoms. Most patients exhibited early improvements in VAS and ODI scores, facilitating early rehabilitation and recovery.