Along with other hyrax species and the sirenians, this species is the most closely related to the elephant. An unrelated, convergently evolved mammal of similar habits and appearance is the rock cavy of Brazil.
Rock hyraxes are squat and heavily built, with adults reaching a length of 50 cm (20 in) and weighing around 4 kg (8.8 lb), with a slight sexual dimorphism, males being about 10% heavier than females. Their fur is thick and grey-brown, although this varies strongly between different environments, from dark brown in wetter habitats, to light gray in desert-living individuals. Hyrax size (as measured by skull length and humerus diameter) is correlated to precipitation, probably because of the effect on preferred hyrax forage
Prominent in and apparently unique to hyraxes is the dorsal gland, which excretes an odour used for social communication and territorial marking. The gland is most clearly visible in dominant males.
The rock hyrax has a pointed head, short neck, and rounded ears. It has long, black whiskers on its muzzle. The rock hyrax has a prominent pair of long, pointed tusk-like upper incisors, which are reminiscent of the elephant, to which the hyrax is distantly related. The fore feet are plantigrade, and the hind feet are semi-digitigrade. The soles of the feet have large, soft pads that are kept moist with sweat-like secretions. In males, the testes are permanently abdominal, another anatomical feature that hyraxes share with elephants and sirenians.
Thermoregulation in rock hyraxes has been subject to much research, as their body temperature varies with a diurnal rhythm. Animals kept in constant environmental conditions also display such variation, and this internal mechanism may be related to water balance regulation. The rock hyrax occurs widely across sub-Saharan Africa in disjunct northern and southern populations; it is absent from the Congo Basin and Madagascar. The distribution encompasses southern Algeria, Libya, Egypt, and the Middle East, with populations in Palestine, Jordan, Lebanon, and the Arabian Peninsula. The northern subspecies was introduced to Jebel Hafeet, which is on the border of Oman and the United Arab Emirates.
The shade of their pelts varies individually and regionally. In particular, the dorsal patches (present in both sexes) of the central populations are very variable, ranging from yellow to black, or flecked. In outlying populations, these are more constant in colour, black in P. c. capensis, cream in P. c. welwitschii, and orange in P. c. ruficeps. A larger, longer-haired population is abundant in the moraines in the alpine zone of Mount Kenya.