This small family of 3 genera and 5 species is restricted to Madagascar. The face of sifakis and avahis is much shortened compared to lemurs, while that of the indri is nearly as long. The external ears of indrids are small and buried in their fur. The pelage ranges in texture among species from woolly to silky, and coloration varies considerably.
All species are vertical clingers and leapers.
Their hind feet are very large but also narrow, and their hallux is well developed and opposable. Hind toes 2-5 are connected at the base by a web of skin, which causes them to be used as a unit against the hallux. Indrids have a curious fold of skin that runs from their chests to their arms, which may represent a vestigial gliding membrane. Indrids have a globular braincase. The bullae overgrows and incorporates the tympanic ring.