Technical Abstract: Entomopathogenic nematodes (EPNs) in the families Steinernematidae and Heterorhabditidae, are biocontrol agents used for suppression of a wide variety of economically important hosts. The ability of the nematodes to persist under field conditions is one of the aspects that challenges efficacy. The problem stems largely from the nematode’s susceptibility to UV radiation and desiccation. However, there are a number of other biotic and abiotic factors that limit EPN persistence as well. The importance of field persistence in biocontrol success can vary depending on the target area of application and expected duration of control. A number of measures can be developed to enhance EPN field persistence including novel formulations, application in infected hosts, and use of amendments. Additional research is needed in developing these approaches further. Research is also required to further understand factors that affect EPN field persistence, particularly on a population and systems level.