Background: Determining the prevalence of degenerative changes by MRI in patients with low back pain (LBP) and lumbar canal stenosis is valuable for better understanding of important LSS issue.Objective: This study was designed to determine the prevalence of disc degeneration changes through MRI images obtained from patients with low back pain and lumbar spinal stenosis.Methods: This was a cross sectional study in which 53 patients (selected through examining 200 MRI images from patients seeking medical care because of low back pain (LBP) and referred to our MRI imaging center) with MRI findings compatible with lumbar canal stenosis (LSS), were investigated between June 2003 to September 2004. Intervertebral disc conditions such as normal status, bulging, and herniation were evaluated in patient’s MRI images.Findings: In 53 patients with lumbar canal stenosis, 34% were women and 66% men (P<0.005). Degenerative disc disorders (especially herniation) were found in 51% of our patients and 49% shown to have isolated bony canal stenosis occasionally with bulging discs. The isolated or combined anteroposterior (AP) diameter narrowing between patients with LBP was 94.35% in the current study compared to the previous estimation in our imaging center (80%) found in 1998. There was 5.65% isolated LR narrowing and 7.5% AP and LR narrowing in our study.Conclusion: Based on our results, 51% of patients had degenerative disc disorder in the form of disc herniation associated with spinal canal stenosis 24.5% with no disc pathology, and 24.5% with bulging discs. Disc degeneration was more prevalent in stenotic group compared to non-stenotic group (51% versus 34% p>0.03).