Background: Mid sagittal diameter {MSD} of lumbar canal is usually compromised in lumbar canal stenosis but enlarged in dural ectasia. The diagnosis is based on comparison between the MSD for an individual and the ‘normal’ for his race and ethnic group. The osteometric data which are available for our population do not take into cognizance the soft tissue dimension. Baseline mean MRI MSD values are necessary for the evaluation of the lumbar canal for stenosis and ectasia Aim: This aims to obtain baseline values of mid sagittal diameter of lumbar canal in asymptomatic study population using magnetic resonance imaging. The relationship between the mid sagittal diameter and age as well as height is also determined. The T1W measurements are compared with those from T2W. Design: This is a prospective cross-sectional study. Setting: The Memfys Hospital for neurosurgery Enugu, between January 2017 and November 2017. Methodology: This is a prospective study of the mid sagittal canal dimension of the lumbar region. The study was conducted on people who are aged between 21 and 50 years. The calculated sample size, using confidence interval formula, was 243. Convenient sampling method was used. People that have neurogenic claudication, neurologic deficit and low back pain that was significant enough to stop them from normal daily activity were excluded. Ethical approval was obtained. The midsagittal lumbar canal dimension was measured at both the disc levels (L1/2 to L5/S1) and mid vertebral levels (L1 to L5) and data was analyzed using the descriptive and inferential statistics. The 0.35-Tesla scanner was used for the study. The relationship between mid-sagittal diameter and age as well as height was determined. The measurements obtained from T1W image were compared with what obtained from T2W images. The measurements were also compared with some other published data from other races. Results: There were 243 participants, made up of 120 females and 123 males. They were further stratified into age groups. The mean values of MSD were L1: 14.13mm, L1/2: 14.2mm, L2: 13.64mm, L2/3: 13.64mm, L3: 13.51mm, L3/4: 13.8mm, L4: 13.79mm L4/5: 13.99mm, L5: 13.67mm, L5/S1: 14.71mm. There was no significant relationship between mid-sagittal diameter and age or height. The mean MSD values were smaller than what was seen in Sudanese and Kurdish but larger than the values seen in Indians. Conclusion The mean MRI values of MSD were lowest at the third lumbar mid vertebral level (L3). The values obtained did not have significant relationship with age and height. The mean MSD values also differed from what was seen in other populations. These values may be used as a reference range for research and diagnosis during lumbar evaluation in this population.