The zoo is dedicated to the accommodation, enrichment, husbandry, and medical care of wild animals. The Johannesburg Zoo houses animals of approximately 3000 different species.
Tours and excursions around the zoo are offered under the auspices of the education department.
It is one of the few places in the world with white lions. The white lions are not albinos. The zoo has had considerable success in the breeding of white lions, which are more sought after than tawny lions by other zoos. To disguise their light colour, the white lions, first discovered in the Timbavati Private Game Reserve, roll in the dirt and thereby blend in - this reduces their visibility to predators and prey.
The Johannesburg Zoo is the only zoo in South Africa to have successfully bred Siberian Tigers. Siberian Tigers are the largest cats in the world. "Twist" is the male Siberian Tiger at the zoo and weighs 320 kg. He is the father of all the Siberian Tigers to be found in South Africa.