tudy design: prospective study. Objectives: evaluation of Transformational lumbar interbody fusion (TLIF) technique for symptomatic degenerative lumbar spondylolythesis with stenosis. Background: there are many options for treatment of lumbar spondylolythesis. Anterior fusion techniques are considered the most effective options theoretically and practically in comparison to the posterior fusion. TLIF through unilateral approach can attack both problems by the same approach via foraminal decompression and through the decompressed area any graft material can be applied. Purpose: to develop stable, painless spine and to avoid complicationsand limitations of other fusion techniques. Patients and methods: 25 female patients with mean age of 47 years (range 41-52) were included. Spondylolithesis affect L4-L5 in 17 patients and L5-S1 in 8 patients. All patients had radicular and mechanical symptoms. All were treated with TLIF and fixed with Pedicular fixation. Results: Evaluation of the results was done through functional and radiologic assessment for an average of. The scoring system adopted wasOswestry disability index (ODI). At final follow-up of an average of 40 months, 72% of patient had minimal disability, 16% moderate disability and 12% severe disability. Conclusion: TLIF is a reliable, effective techniques that allows a three-column fusion through a single approach in comparison to the less effective posterolateral fusion and more demanding anterior approach