Introduction: The technique of inter-pedicular screw fixation for the purpose of spinal fixation has gained enormous importance in the recent years. The choice of screw for the procedure is determined by the minimum (transverse) diameter of the pedicle .Morphometric data on the diameters of the pedicles are therefore useful in preoperative planning and in designing pedicle screws.Most of the previous study of the morphometry of pedicle is based on white population using x-rays and CT scans. Therefore the present study was conducted in the Western region of India in state of Rajasthan to measure the morphometry of pedicles in relation to trans-pedicular screw fixations as well as to distinguish differences in the morphometry of pedicles in men and women of different age groups using MRI technique. Aims and Objectives: To evaluate the sexual differences in transverse and Sagittal diameters of lumbar vertebral pedicle. Also to determine the difference of diameter in the pedicles of different age groups and finally to determine the morphometry of pedicles in relation to trans- pedicular screw fixation in the region of Rajasthan. Materials And Methods: MRI scan of 1000 patients (both males and females) between the age group of 20 to 60 years, with the history of low back pain reporting to the outpatient department of Neurosurgery, Orthopedics, Rehabilitation and inpatients admitted in various wards for complaints of disc protrusion, disc extrusion, spondolysthesis (not associated with gross vertebral body collapse) of S.M.S. hospitals, Jaipur formed the material for the current study. Results: There is a cranio__ampersandsignndash;caudal increase of transverse and sagittal diameters from L1 toL5 vertebrae. Dimensions of male population are significantly higher than female population with respect transverse diameter and sagittal diameter. With the above parameters the size of the screw for transpedicular screw fixation can be derived.