Introduction: Lumbar disc herniation is one of the most common spinal degenerative disorders which leads to low back pain and radicular leg pain. The aim of this study is to evaluate the clinical and radiological outcome of Instrumented Posterior Lumbar Interbody Fusion in L4-L5 massive lumbar disc herniation with instability. Materials and Methods: It is a prospective clinical study of 10 consecutive patients. The duration of study is from July 2015 to July 2016. The duration of follow up range from 12 to 18 months. Clinical outcome is assessed using Oswestry Disability Index (ODI), Visual Analog score (VAS), The Japanese Orthopaedic Association (JOA) score. Radiological outcome on fusion by using Modified criteria of Lee et al. Results: Of the 10 patients (8 male and 2 female) with the mean age of 60.9 years. Average follow up duration is 14 months. Mean BMI of the patients is 26.14 + 1.95 kg/m 2 . The difference in pre-operative and post-operative patient's ODI, VAS and JOA scores are significant (p value < 0.05). Surgery restores the disc height and at a mean follow up of 14 months, 8 patients shows possible fusion and 2 patients shows possible pseudoarthrosis. Conclusions: Corticocancellous Laminectomy bone chips with single cage provide adequate fusion and stability in L4-L5 Instrumented Posterior Lumbar Interbody fusion.