Background Data: Degenerative lumbar spine disorders are common pathologies that usually affect females in their sixth decade or older. Patients usually present with various symptoms, including back pain, radiculopathy, or neurogenic claudication, among other less common presentations. Different fusion procedures are available to manage these problems. Purpose: This study was designed to evaluate the clinical and radiological outcome of transforaminal lumbar interbody fusion (TLIF) and posterolateral fusion (PLF) in managing degenerative lumbar disorders. Study Design: A prospective study. Patients and Methods: This study was conducted on patients with degenerative lumbar spondylolisthesis and degenerative lumbar spinal stenosis who underwent lumbar spine fixation with either TLIF or PLF. Patients were randomized into two groups according to the operative procedure: Group A (20 patients) underwent TLIF and Group B (20 patients) underwent PLF. Patients were followed up and assessed for back and leg pain, functional disability, and spinal fusion. Results: We found that both TLIF and PLF improve disability and pain in patients with degenerative lumbar disorders. TLIF was found to be superior to PLF as regards achieving radiographic outcomes. We did not find strong evidence to support the use of interbody fusion along with transpedicular fixation compared to traditional posterolateral fusion in the treatment of degenerative lumbar disorders, taking into consideration the higher material costs added with interbody fusion. Conclusion: The reported data in the present study suggest that both TLIF and PLF provide improvement of disability and pain in patients with degenerative lumbar disorders. They also suggest that TLIF is superior to PLF when comparing the achievement of radiographic fusion. However, there is no significant clinical outcome difference to recommend using TLIF over traditional PLF in treating degenerative lumbar disorders, especially with the higher treatment costs related to the use of interbody fusion. (2020ESJ217)