Many zoos worldwide exhibit New World monkeys in mixed-species exhibits, with monkeys, reptiles, birds or other mammals. Many of these exhibits are very successful, providing a more dynamic environment for the inhabitants and a more interesting and informative display for visitors. Analysis of previously published literature on the success and failure of species combinations reveals a higher success ratio for naturally associating species, but that sympatry alone does not predict the likelihood of success. Nonetheless, careful consideration of choice of species and an enclosure purpose-designed or modified with features for the chosen species can increase success. Environmental enrichment can be designed to promote positive and natural interactions between naturally associating species. There are some precautions to be taken during the introduction of the species to increase the likelihood of compatibility, and continued monitoring of the exhibit with enclosure modification if necessary will increase the chances of longer-term stability.