There are 11 species in 3 genera in the family Indriidae. The most diverse group are the sifakas (Propithecus), with 7 species. There are also 3 species of woolly lemurs (Avahi) and 1 species of indri (Indri). As in other lemuroid families, species diversity in Indriidae has increased substantially in recent years, going from 5 species recognized in 1991 to 11 in 2005.
Indriidae includes 5 recently extinct genera, representing 7 species. These species became extinct between 500 and 1,000 years ago. The extinctions of all of these species are thought to be directly related to environmental disruptions and hunting by humans soon after their immigration and expansion on Madagascar.