Sex differences in linear and area dimensions of the foramen ovale and external opening of the carotid canal were analyzed in a documented French sample (35 men and 32 women). The results demonstrated that a low level of sexual dimorphism is present in the cranial base foramina of this sample, with only two-thirds of the examined variables exhibiting statistically significant differences (p less than 0.05) between the sexes. The cross-validated sex classification accuracy rates obtained for univariate and multivariate discriminant functions ranged from only 54.7 to 72.1 percent. In addition, measurements of the cranial base foramina were found to be difficult to record with precision, with intra-observer error percentages ranging from 2.35 to 4.23 percent. Error rates of this magnitude may result in the misallocation of specimens. Therefore, osteometric analysis of the foramen ovale and carotid canal external opening cannot be recommended as a useful method for cranial sex assessment in this population group. Abstract published by arrangement with John Wiley & Sons.