The ischiopubic index was studied in adult pelvic X-ray films of subjects aged eighteen to seventy years. A total of 120 X-ray films made of 60 males and 60 females were collected from LUTH, Lagos State. The ischiopubic index was calculated by dividing the pubic length by ischial length and by multiplying by 100. The mean ischiopubic index for males was 101.05 ± 16.65 and that of the females was 115.99 ± 18.5. Sex differences of these indices were statistically significant () for both sexes. The mean length of the females pubis was significantly longer than that for males (), and similarly the mean length of ischium in males was significantly longer than that of the females (). Using X-ray films, sex could be assigned using demarking points to 47% and 50% females in Lagos State. In conclusion, this research has provided evidence that the ischiopubic index and the demarking points are reliable in sexing the hip bones of Nigerians (using X-ray films). Thus the ischiopubic index may be of value in forensic and archaeological analyses and in solving medicolegal cases. 1. Introduction The innominate bone has long been recognised as one of the best skeletal indicators of sex in an adult individual. Methods have been developed which provide criteria for sex determination of adults using features of the innominate bone [1, 2]. Various studies have shown extensively that the hip bone is an ideal bone for sex determination because it reflects not only the general differences between the sexes but also the special adaptation of the female hip bone for child bearing [3–5]. lbone of females was much longer than those of the males. This has been confirmed in adult black Malawians . In the past many workers have evolved various metrical parameters and indices for sexing of the hip bone of which one of them is the ischiopubic index. This index was used efficiently where the pubic was separated and could determine sex in a high percentage of bones. The ischiopubic index is useful in sex differentiation . It is obtained by dividing the length of pubis by the length of the ischium. This index is one of the determining factors of the size of the pelvic inlet and is significantly higher in females than in males . The results obtained will contribute to comparative data base for Nigerians  as well as compare those of other races. 2. Materials and Methods A total of 120 radiographs of the anterior-posterior view of the pelvis were collected comprising 60 males and 60 females. All the radiographs were collected from the University of Lagos Teaching Hospital (LUTH),
F. P. Schulter-Ellis, D. J. Schmidt, L. A. Hayek, and J. Craig, “Determination of sex with a discriminant analysis of new pelvic bone measurements—part I,” Journal of Forensic Sciences, vol. 28, no. 1, pp. 169–180, 1983.
T. B. Ekanem, A. J. Udongwu, and S. P. Singh, “Radiographic determination of sex differences in ischiopubic index of a Nigerian population,” The Internet Journal of Biological Anthropology, vol. 3, no. 2, 2009.
T. Iguchi, S. Irisawa, Y. Fukazawa, Y. Uesugi, and N. Takasugi, “Morphometric analysis of the development of sexual dimorphism of the mouse pelvis,” Anatomical Record, vol. 224, no. 4, pp. 490–494, 1989.