Background: Lumbar degenerative disease (LDD) is a chronic condition of the lumbar spine affecting the vertebrae, facet joints and intervertebral discs and commonly causing low back pain (LBP) which may be due to instability of the motion segment. The aim of this work is to evaluate the relation between lumbar degenerative disease and lumbar instability. Methods: Sixty patients (20 females and 40 males) complained of LBP and/or sciatica. They were studied in 4 groups categorized according to magnetic resonance imaging (MRI) grading using Modified Pfirmann Disc Degeneration Scale: Group I (19 patients grade IV), Group II (16 patients grade V), Group III (14 patients grade VI) and group IV (11 patients grade VII). In addition to full history taking, all of them were subjected to thorough clinical examination including pain visual analogue scale (PVAS) to assess pain severity, Routine lab. investigations and Radiological examination (X-Ray: Static and dynamic, CT and MRI). Results: No significant differences between four groups regarding clinical data (LBP, sciatica, full motor power or SLR) were found but straight leg raising (SLR) angles were lower than normal within all groups, while PVAS showed significant difference between four groups (P<0.05). X-ray findings showed significant differences (P<0.05) among different degenerative grades. By correlating PVAS with disc height (DH) ratio and CT facet grading there were positive correlation, while Angle difference were negatively significantly correlated to DH ratio and correlated to CT grading positively. Conclusion: severity of LBP is directly correlated with the grade of disc degeneration found in MRI and both are directly correlated with the DH ratio and angle difference measured in X-ray and the degree of facet arthropathy seen in C.T.