BACKGROUND: osteoporotic elderly patients with lumbar spine problems needing stabilzation are more likely to be encountered with recently and constitute a major concern to the spine surgeon due to the increased rate of mechanical failure at the osteoporotic spine-implant interface AIM OF THE STUDY: we tried to evaluate the validity of CBT to stabilize the lumbar spine when indicated in osteoporotic patients from Jnuary 2018 till December 2021 at the Neurosurgery department Benha University Hospital. PATIENTS AND METHODS: a retrospective study for the medical reports of all patients operated upon by the cortical bone trajectory technique (CBT) to stabilize the lumbosacral spine in osteoporotic patientsfrom Jnuary 2018 till December 2021 at the Neurosurgery department Benha University Hospital. RESULTS: 20 osteoporotic patients were admitted at the Neurosurgery department Benha University Hospital from Jnuary 2018 till December 2021 with the diagnosis pf lumbar instability that required fixation due to lithesis in 10 patients, recurrent disc herniation in 8 patients and foraminal stenosis in 2 patients. After 24 month nean follow up period there were decrease in VAS for low back pain and fusion occurred in 90 % of patients CONCLUSIONS: Cortical bone trajectory screws are valid to stabilize the lumbar spine in osteoporotic patients with lumbar instability due to different pathologies.