The pelvis and skull are frequently examined for the expression of sex-linked traits as are the humeral and femoral head dimensions. The second vertebra allows for rotation of the head, which is larger in males than in females. The axis is positioned close to other traits that have been shown to exhibit dimorphism, such as the mastoid process, gonial region, nuchal area, and the occipital protuberance. To explore which dimensions of the axis differ the most between females and males, and investigate its relationship to age, 149 individuals from the W.M. Bass Osteological Collection at the University of Tennessee, Knoxville were measured using 13 linear distances. The three age cohorts included 30-35, 50-55, and 70-75 years. The results indicate that all the traits show significant differences between the sexes. Using discriminant function analysis, predictive functions were created to estimate the sex of unknown individuals using 6 traits, 4 traits, 3 traits and 2 traits.