Background Data: spondylolisthesis is the slippage of one vertebral body in respect to the adjacent vertebral body causing mechanical or radicular symptoms or pain. It can be due to congenital, acquired or idiopathic causes. Spondylolisthesis is graded based on the degree of slippage of one vertebral body on the adjacent vertebral body.it is commonly occur at at the L4-5level then at L5-S1 level. [1] Purpose:. The aim of this work is to study the different prognostic factors of surgical treatment of spondylolisthesis . Study Design: This is a prospective &retrospective study. Patients and Methods: This is a retrospective and prospective study that includes 92 patients with lumbar spondylolisthesis that operated by transpedicular fixation at Neurosurgery department at Benha university hospitals from octobre 2018 to October 2020 . All patients will be subjective to history taking regarding name, age, sex, address, occupation and smoking. All patients will be examined neurologically regarding general examination and local examination as motor power, sensation, reflexes, sphincters and will be investigated by x-ray dynamic views, CT, bone scan and MRI lumbosacral spine. The patients will be followed up immediately post operative by CT scan and clinicaly regarding symptoms that the patient was complaining of before operation. The patients will be followed up every 3 months clinically and by x-ray , CT and MRI if needed with follow up period 6-18 months. Results: we found multiple prognostic factors that affect surgical outcomes either succeeded or failed cases according to weight , level of lithesis ,grade of lithesis, claudication distance, duration of operation , blood loss &hospital stay .Conclusion: multiple prognostic facors affect surgical outcomes either succeeded or failed cases