Mahale contains a chimpanzee sanctuary with a population over 1,000 and, like its neighbor Gombe, is home to research projects as well. Yellow baboons, red colobus, red-tailed and vervet monkeys also live in the park, also commonly seen are bush-babies, bush-pigs, bushbuck, blue duiker, civet, hyrax and white-tailed mongoose.
Also present but harder to find are buffalo, elephant, giraffe, leopard, llion, porcupine and various types of antelope. Bordered by Lake Tanganyika to the west, over 250 different species of fish have been found here.