Of the monkeys in Africa, the colobines comprise 19% of the 16 genera and 30% of the 79 species. They occur all across tropical African from sea level to 3,400 m above sea level, and where temperatures range from -7°C to 41°C and mean annual rainfall ranges from 50 cm to 1,100 cm. Ninety-six percent of the 24 species of Africa’s colobines are threatened with extinction, whereas 68% of the subspecies are threatened with extinction. Six of the species are ‘Critically Endangered’, including one that is probably already extinct. The two primary proximate threats to colobines in Africa are forest loss and hunting by humans, while the ultimate threat is humans and their widespread over-exploitation of natural resources. This chapter reviews the biological traits that make Africa’s colobines especially susceptible to extinction through forest loss and hunting, the threats they face, and the impacts of those threats. Predictions are presented concerning which species of African colobine will be among the first extinctions and where Africa’s colobines are expected to persist for at least the coming 30 years. Finally, this chapter presents an overview of the main conservation actions that Africa’s colobines require and gives priorities for research that will support their conservation.