Deforestation is a global issue, and is prevalent throughout the geographic range of many primate species. Although deforestation has occurred for tens of thousands of years, deforestation in the twentieth and twenty-first centuries was primarily driven by agricultural crop expansion, cattle farming, fire, logging, mining for gas, oil, or minerals, transportation, and urban development. Many primate species range in areas that have been heavily deforested, or areas that are under current deforestation threat. As a result, some primate populations have experienced severe population declines, and some forests are now primarily empty of nonhuman primates and other wildlife. In Uganda, Madagascar, and the Atlantic Forest of Brazil, deforestation has been ongoing for several decades, and as a result the remaining forest is often patchily distributed in small forest fragments. However, very recent deforestation in Brazil, Paraguay, the Democratic Republic of Congo, and Indonesia may critically impact primate conservation in the near future.