Morphometrical analysis of 30 dry stored atlas (C1) vertebrae was performed in order to determine the appropriate length of the screws to be placed on the atlas via posterior approach. In addition, a 3D CT scanning was performed on all samples and angles and lengths were measured on radiological data derived from CT scans. The previous morphometric studies carried out on C1 screw fixation were meticulously reviewed. The literature review has revealed that two non-assessed measurement parameters akin to the ideal screw length have been generated in this study. The first of these parameters, the length of the screw in the saggital plane, has been found 17.8 mm on right and 18.72 mm on left sides. The length of the screw in the vertical plane was found 19.06 mm on right and 19.26 mm on left sides. It's clear that the differences between the interval values of the two measurement parameters range between 5.65 mm and 9.25 mm at minimum. According to the measurements and the literature review carried out so far, there is not a standard screw length for C1 lateral mass screwing technique. The screw length is different for every individual. The surgeon to apply C1 lateral mass screwing must calculate the appropriate screw length via pre-operative cervical CT examinations and use the appropriate-sized screws in the operations.