The pars basilaris of the human occipital bone is reported to be of considerable value for age estimation in juvenile skeletal remains between early fetal periods and 6 years of age, when it fuses to the remainder of the bone. The aim of this investigation was to examine the relationship between various dimensions of the pars basilaris, and assess their reliability for accurate age estimation. The results confirm the usefulness of the bone in this respect and they are discussed in the light of differential growth of the pars basilaris, and in the increase in dimensions of the boundaries of the foramen magnum.