In the past decade, there has been increased use of mass-produced or collected insect predators for the control of arthropod pests. Nevertheless, there has been continued discussion regarding their effectiveness. We present a literature review that compiles information on the augmentation of predaceous insects. A taxonomically diverse assemblage of insect predators has been experimentally tested or commercially used against a wide range of pests. The effectiveness of tested predators in the different augmentation programs varied greatly, depending on target pest, target crop, release method, and release rate. The most successful programs involved the release of predators inside an enclosed system (e.g., glasshouse). We also note that most experiments testing predator effectiveness were not conducted within the confines of a commercial release program. In fact, many of the release methods or release rates tested are not practical in commercial operations. The biological characteristics of insect predators used in augmentation programs are reviewed, with particular reference to predator dispersal and predator–prey, predator–predator, and predator–habitat interactions that can reduce the impact of predator release. Methods to evaluate the success of predators released are reviewed briefly, along with a summary of our evaluation efforts on releases of Chrysoperla spp. for control of leafhopper pests in vineyards. Through this review, a call is made for renewed efforts to complete efficacy studies and improve augmentation programs. We propose that predator augmentation programs should include (1) guidelines that match the released predator’s biological features to the target pest and crop; (2) improved release methods, including release rates that have scientific and economic justification; and (3) new research directions, especially with regard to the development of mass-rearing techniques and the evaluation of insect predators not currently used in augmentation programs.