The question as to whether the black rhinoceros occurring in South West Africa should have subspecific status or not, is still a debatable point. This uncertainly is mainly due to a lack of sufficient material available to workers. Sixteen measurements were taken of each of the 18 black rhinoceros skulls collected in South West Africa. Similar measurements were then taken of each of the 20 skulls collected in Natal. These measurements were then analysed statistically. Mayr, Linsley and Usinger's (1953), interpretation of the 75 per cent rule parameter was used. Keywords: Diceros bicornis, Interperygoid, Kaokoveld, Lacrimal length, Limpopo drainage system, Opsiceros occidentalis, R. keitloa, Rhinoceros niger, Skull, Zygomatic width.