In 1983 the number of Squirrel monkeys living in their natural environment was estimated with some 200.000 individuals. 1996 only 2000 to 3500 were left. In Panama Squirrel monkeys were believed to have reached total extinction until some groups were discovered.The natural environment of the species was almost completely turned into farmland and pasture during the last decades.

The size of protected habitats within the distribution areas is very small, so a lasting survival of the species in these areas is not secure. Inbreeding or sudden diseases increase the risk for extinct. For the time being little effort was made to establish a network for the populations living isolated from each other. The Central American Saimiri is protected by a number of international agreements. (CITES 2003: Appendix 1 IUGN 2004: threatened, stock shrinking).