Background and Objectives: - This study was conducted to determine the relationship of LF thickness with spinal canal diameter with LF thickening identification at a specific lumbar level. The relationship of lumbar spinal LF thickening with age and sex using magnetic resonance imaging (MRI) was also assessed. Materials and Methods:- This was a prospective study done on 60 cases at IGIMS, Patna. Patients were referred from different department specially neuromedicine and neurosurgery department. Measurements of spinal canal diameter and LF thickness were taken from T1- and T2-weighted axial MRI scans using optima MR360/ 1.5T MRI. Results: A total of 300 spinal canal diameters, along with 300 intervertebral disc heights and 600 ligamentum flavum thicknesses with mean value of bilateral LF thickness were assessed from MRI scans. The most common involved level with maximum stenosis was L4-5 (53.33 %) which needed surgery with more non-DSS involvement. Maximum thickness of LF with mean value of 9.4 mm was noted at L4-5 level (53.33 %) which was associated with maximum spinal canal stenosis. Conclusion: This study shows significant difference in the relationships of spinal canal diameter, LF hypertrophy in DSS and non-DSS group. Thickness of the ligamentum flavum increased with age and this increase is most pronounced at the lower lumbar levels which lead to lumbar spinal stenosis of variable degrees, specifically in Non-DSS group.