As a direct consequence of the generally larger body size of the male, it is reasonable to expect the adult human vertebral column to display sexual dimorphism. However, there is a distinct paucity of literature concerning sex-related variation in vertebral dimensions. This study examines the accuracy with which sex may be predicted from vertebral body diameters. In a sample selected from a documental skeletal series, sex could be correctly assigned with an accuracy approaching 90%. This degree of sexual differentiation is of value for both the forensic and archeological identification of human skeletal remains. An interesting relationship was noted between the degree of expression of sexual dimorphism and the role of each area of the vertebral body in body weight transfer. The posterior aspect of the vertebral body is involved in the transmission of body weight both vertically and laterally from the transverse processes. This area was consistently less dimorphic than the anterior region of the vertebral body, which is more concerned with the transfer of body weight from the vertebra above.