Background: Degeneration of lumbar spine is a common and age related finding in the normal population. Eighty percent of adult population suffer from at least one episode of low back pain during their life time. Objective: The present work aimed to study the midsagittal dimensions of lumbar vertebrae, intervertebral discs, and vertebral canal in normal Egyptian population in different age groups in both males and females using MRI. Materials and methods: A retrospective study of MRI midsagittal images of lumbar spine was carried out for normal Egyptian population whose ages ranged from 20 to 60 years old and divided into 4 age groups (decades). The parameters measured for the discs were; anterior, central, posterior disc heights, relative disc height index and anteroposterior disc diameter, while the parameters measured for the vertebrae were; central height, anteroposterior diameter, midsagittal canal diameter and canal/ body ratio. The data were statistically analyzed and tested for significance between age groups and between males and females. Results: The measured parameters of the discs increased with age progress with significant differences at different levels between age groups. Also, they were found to be greater in males than females with significant differences. The relative disc height index showed a constant relationship between males and females. For the vertebrae, the parameters showed no significant differences related to age progress, while they were greater in males than females at all levels in all age groups. The midsagittal canal diameter and canal/body ratio indicated that the canal diameter decreased steadily from 3rd to 6th decade and was more capacious in females than in males. Conclusion: The measurements obtained in the present study can be considered as a database which can be helpful to clinicians, therapists, and researchers as ready references of lumbar spine in normal adult Egyptian population. Any deviation from these values should be correlated with clinical findings.